m1a rifle won't chamber next round

[lowlytech]

First off I consider this the best place for reloading information. This site has given me so much information to process I am truly greatful for it. I am sorry my first post has to be a question about a problem...

I have a M1a that I purchased brand new in a M21 configuration from Springfield. I have only shot factory federal gold metal match (168+175) without a single hicckup. It probabaly has chewed threw 200 of these rounds. I decide I want to load up my own load for this rifle. My question is my rifle doesn't seem to want to cycle properly with my loads I made. The gun fires and recoil seems standard, but it won't chamber the next round. It is like the load is not powerful enough to cycle the bolt back completely. about 30 percent of the cartridges will fail to eject properly and the bolt will close on the fired brass, the others will eject but won't strip the next round into the chamber ever. Also at the last round the bolt will never lock back. The obvious thing would be to put more powder in the case, problem is according to my sierra reload book, I am at max load condering I take 1 grain of powder away for the thicker military brass. I have only tried the same bullet, but have tried two different rifle powders with the same result. My specs are as follows..

Press: Dillon 550B progressive /w dillon .308 dies (carbide)
Bullet: 175 sierra matchking
brass: LC 05 once fired, trimmed to 2.015
primer: CCI No. 34
Powder 1: IMR 3031, 38.1gr Average FPS (2405)
Powder 2: Varget, 40.5gr Average FPS (2406)
O.C.L.: 2.805"
Barrel: 22" match barrel, 1:10 Douglas

The primers don't show any signs of overpressure that I can tell. I guess my main question would be do you think I would be safe given the fact that the recoil doesn't seem excessive to go ahead and load an additional grain or 2 to see if that makes the gun cycle properly, or is there another way to approch this issue. Just didn't want to end up with a blown up gun, or worse and chunk of metal in my arm. Fear of Kabooms are what kept me from jumping on the reload wagon until recently. 308 is all I have ever loaded and am not to confident yet to approch this without someones input. Pics of some of the fired cases are Here...

Thanks.

 

[Waldog]

If you are using once fired LC brass and did not shoot it your self your using brass that has been fired in a machine gun. 99% of surplus LC brass has been fired in a machine gun. MG chambers are very generous in order for the cartridges to feed when the gun is HOT. As a result, the brass is stretched in every dimension. You should full length resize all semi--auto brass anyway however, if standard full length resize doesn't do the job, RCBS and other make a "Small-Base" die that resizes back to minimum dimensions. Be aware that this "stretched" MG brass is certainly useable but, it will not have the case life you would expect. You need to carefully monitor the cases for neck splits and pending head separations. Be aware that military brass is thicker and generally has about 10% less case capacity. This reduced capacity increases chamber pressure. You usually can not load surplus brass to "maximum" listed in many loading manuals

Now if you can get LC Match brass, that's another story. It's premium brass, without crimped primers is very consistent and seems to last forever. I have some 1956 LC Match 30.06 brass that I still use.

 

[243winxb]

When i look at the load data on the Hodgdon website, you loads are to light. Add more powder .5gr at a time till the rifle cycles ok. The starting charge of powder using Varget is listed at 42.0gr. Starting for 3031 is 38.0gr.

 

[hancjamk]

Did you try a different magazine? It happened to me... After 200 rounds the 10 round mag that came with the rifle stopped cycling... At first I thought it was my reloads, as well...

 

[Kevin Rohrer]

1. Yes, your loads look to be too light. The Hornady book has a section on loading for the M1A.

2. Save some of the brass you fired thru it and get yourself a decent vernier caliper and the Hornady (or other similar) headspace gage that works w/ the calipers. Then use the calipers, headspace gage, and your once-fired cases to determine the correct headspace for your rifle. Then set your dies for .002-.004 shorter than the headspace measurement.

 

[lowlytech]

Thanks for the replies. I will try adding some more powder. I only have the sierra reload manual as my main reference. I guess are they covering themselves for the broad range of all 308 rifles? I find it strange that their stated max load for my powder with the 175grain bullet was at or below the starting loads from the manufacturer.

I also have several hundered brass Federal cases from the GMM that I fired I can try, and I did only have my 10 round mag with me at the range. I have several other 20 round mags I could try. Now that I know about the loads being a little light and you guys confirming that I feel a little better to try to increase the load a bit cause that is what seemed to be the problem in my head was not enough punch to cycle the bolt back cause the recoil seemed mild/boardline normal from what I remember.

Now that I got some direction I will get prepared for and report back here with my current status with the rifle. I will try all the recommendations and probably be able to get back to the range no sooner than next friday. I might not get the headspace thing done in time, but I will certainly try.

Thanks again for the input on this

 

[M ammo]

get better dies,,, I had the same problem with a DPMS LR 308,,,

get Full leangh,,, SMALL BASE dies,,,,

size the brass then,,,

Make sure you trim your brass,,, and trim it a lil shorter than factoy spec,,

load as you will,,,

Full leangh,,, SMALL BASE dies,,,,

money well spent,,

 

[MEHavey]

What you describe is not failure to chamber (which would be a brass/resizing problem), but failure to eject/cycle, i.e., short-stroking. That's purely a function of residual pressure once the bullet passes the gas port. Pressure from fast powders (like 3031) tend to fall off more quickly by the time things reach that point. Not having enough of even a medium-burning powder will do the same thing.

You should be loading that 175SMK into the mid-high 2500's (2550-2560fps regime) to equal military-issue/match loadouts. 3031 probably isn't the best powder to use behind that heavy a bullet for any length of time, but Varget should do fine.

Before you get too far down the road, you should read this:
http://www.zediker.com/downloads/14_loading.pdf

 

[243winxb]

brass: LC 05 once fired, trimmed to 2.015

2.015" is the maximum case length. Trim to length is 2.005" Your OK at 2.015" as there is a "safety margin" in the chamber that will except slightly longer brass.

 

[P-32]

Full leangh,,, SMALL BASE dies,,,,

I'm going to argue a bit about the need for a small base die. If anything the OP should get the Forster NM 308 die. I've loaded lots and lots of 223, 308 and '06 for use in my gas guns. To date I've never found the need to use a small base die.

I think if you up your powder charge a bit your problem will go away. Varget is a fine powder for 308, but one should not rule out IMR 4064 or IMR 4895.

 

[Kevin Rohrer]

or BLC-2.

Small base dies = not necessary

 

[hancjamk]

Small base die... Page 4 and 5 on the link that MEHavey posted explains everything. I find this article more as fact and everything else as personal preference.

 

[jr_roosa]

You really need a chronograph. If you are getting good velocities from your loads and still short-stroking then you need to change powders since more powder will be sending you towards overpressure land. Also it might make you think that there might be a problem with the gas system that needs to be looked at.

If your velocities are slow then you are probably are safe upping the charge in increments.

-J.

 

[MEHavey]

Again, the OP's issue is cycling, not chambering/bolt closure.
He needs ~12,000+ at the gas port which is 15 inches down the (22") barrel to cycle properly.

- 175SMK/3031/38.1grains, Quickload says pressure at the port is 11,700psi (MzlVel=2470)
- 175SMK/VARGET/40.5grains, QL says port pressure is 11,400psi (MzlVel=2426)

Suggest you consider:
- IMR3031/39.6grains
- Chamber Pressure= 50,650psi
- Port Pressure= 12,050psi
- MzlVel=2550fps

VARGET can't get you the velocity you need w/ the 175 w/o getting hot (chamber) pressures

Suggest you better (best) consider:
- IMR4895/41.5grains
- Chamber Pressure= 48,800psi
- Port Pressure= 12,500psi
- MzlVel=2525fps

(Check to see if IMR4895/41.0 grains works first. If it does, stick with that.)

 

[Slamfire]

Well I am puzzled.

I just looked over my chronograph data in my Match M1a's (Douglas 1:10 barrels) and my rifles functioned with some rather low velocity stuff.

[SIZE="3"]
174 FMJBT 39.0 grs AA2520 wtd  Mixed LC, WSR(brass) OAL 2.800	

T = 50 °F 	10-Mar-02

Ave Vel =	2335						
Std Dev =	25						
ES =	82						
Low =	2282						
High =	2364						
N =	10						
poor group
		
174 FMJBT 42.0 TALON Surplus 4895 CAVIM90 CCI#34 OAL 2.800"			
	 				
18 May 2008 T =  68 °F					
						
Ave Vel =	2443					
Std Dev =	17					
ES =	64					
High =	2477					
Low =	2413					
N =	15					
good group


168 Hornady Match  41.0 grs Varget  wtd Lot 4295 Mixed LC WLR OAL 	2.8		
3-Oct-05	T = 87 ° F
					
Ave Vel =	2486					 	
Std Dev =	19					
ES =	61					 	
Low =	2447					
High =	2508					 	
N =	12		 				
rounded primers							
poor accuracy
					


168 Nosler 40.0 grs IMR3031 wtd Lot FE23B LC90  CCI#34 	OAL 2.780"	
T = 52 ° F	2-Feb-08						
							
Ave Vel =	2540						
Std Dev =42						
ES =	101						
High =	2585						
Low =	2484						
N =	5					
[/SIZE]

Groups were not good at the low end but at least my rifles functioned. My rifle functioned with 41.0 grs Varget and a 168, don't understand why yours won't with a 175. Still I would bump it up as I got better accuracy around 42 to 43.

Take a look at my IMR 3031 load, I shot that out to 300 yards and it worked well.

I recommend full length small base sizing and setting up your sizing dies with a Wilson gage. I remember a fellow competitive shooters whose brass was too tight in the chamber and he experienced failures to extract, maybe eject.

Just today at the rifle match, I took my cleaning rod and knocked out a round out of an AR15. The case that was not properly sized below chamber dimension. It was so big the bolt could not rotate all the way into battery, but the bolt had enough momentum that the case was partially resized into the chamber. Of course the case was stuck in the chamber, the extractor could not pull it out and because the lugs could not turn into battery, the round could not be shot out.

If I had a dollar for every case I have knocked out of someones chamber, I would probably be up to $20.00. Don't think I would be up to $50.00, but might be getting close.

Always small base size cases for these gas guns. When you see enough malfunctions you will figure out that is the best way to go.

The fact your rifle shoots Federal factory without a problem tells you its reloads.

 

[MEHavey]

...and my rifles functioned with some rather low velocity stuff.

I can only 'suspect' that in having a brand new SA, things/springs might yet be a little "stiff" w/ the OPs's rifle -- ergo a bit more pressure required `til shot in.
(And as afterthought, what is the port diameter on your Douglas if you know?)

FWIW: I small base for both the AR and the M1A. By comparison, the Garand seems to eat everything out of a regular FL die without even the slightest hint of a hiccup.

 

[Sunray]

Hi. 38.1 is .1 over minimum. Nowhere near max. Even with milsurp brass(reduce the charge by 10%, not 1 grain.). 40.5 of Varget is fine too. 1.5 grains under minimum. That's over the 10% reduction, but ok. Your rifle should function properly with either load. Especially the 3031 load.(re-think IMR3031 for match ammo. Think IMR4064.) Your OAL is 5 thou too long as well. 5 thou won't make much difference though. Certainly won't cause a feeding/cycling issue.
"...Always small base size cases for these gas guns..." You don't need SB dies. Regular FL dies are fine.
You don't need CCI "milspec" primers either. They're just a brilliant marketing gimmick for magnum primers. And cartridges do not have headspace.
Anyway, you don't have an ammo problem if it feeds the first round. You have a gas issue. Like MEHavey says, it's short stroking. Not enough gas to cycle the action.
Did you clean the rifle? Particularly the gas system.
Is your gas system turned on all the way? As daft as that sounds. Look at the Spindle Valve and make sure it hasn't moved. Part 25.
http://stevespages.com/ipb-springfield-m1a.html
You don't have a mag issue either, since it'll feed factory ammo.
Oh and don't bother calling SA Inc. Using reloads voids their warrantee.
"...port diameter on your Douglas..." M21 M1A's come with it. SA's QC isn't that bad, especially as they don't make the barrels.

 

[lowlytech]

I finally got to go try some new loaded rounds today cause Friday didn't work out too well with going to the range. I wanted to report that the function seems unchanged with the new loads. I made six different batchs with only Varget and the really strange thing is the last 2 loadings the brass case was not even the slightest bit warm. Pressure seemed more apparent, but primers look normal, the 43.0 group started showing rings around the primer. The loads were as follows...

Varget, 175gr SMK, LC05 brass
40.7 Avg. vel 2469, cases would eject, wouldn't load next round, cases hot
41.1 Avg. vel 2455, cases started to not eject, unchanged otherwise
41.6 Avg. vel 2525, same as 41.1
42.2 Avg. vel 2520, consistantly had to pull the bolt back to eject fired cases
42.5 Avg. vel 2542, same as 42.2, but noticed spent cases are not warm
43.0 Avg. vel 2564, no apparent change from last sample.

In summary it seems the more powder charge the more it is expanding? and getting stuck in the chamber. On the cases where they did not eject after firing I started feeling more and more resistance when pulling the bolt back to eject them as the charges increased. No terrible force by any means, but you could notice a hesitation right around the base of the case. I guess too that the higher charges are not igniting the powder properly due to the cases not being warm at all to the touch immediately after firing. I am going to go back through all the posts cause I think there are some I haven't got to read since I hadn't checked back here since mid last week. I am going to try to make a point to go to the range again tomorrow and have some of the commerical 308 brass I have loaded as well as take some factory 168Gr. Gold Metal Match I know was working previously just to make sure I haven't lost my mind and that the gun still fuctions properly.

 

[lowlytech]

I have some progress to report. Went to do some additional tests and I think I have deduced that the LC brass is the problem. I used the same 10 round mag and had everything else setup the same in the press and dies in each load (except #1). Also tested an additional powder type, TAC.


#1 Factory, Federal gold metal match, all rounds functions 100%, avg. vel 2580
#2 Reloads, federal and PPU brass, 175Gr, 42.2 gr varget 100% function!!
avg. vel 2521
#3 Reloads, LC05, 168Gr SMK, 42.5 Varget, didn't eject, didn't register on chrono, or error
#4 Reloads, LC05, 175Gr SMK, 38.0 TAC, didn't eject, Avg. Vel 2252
#5 Reloads, LC05, 175Gr SMK, 40.1 TAC, didn't eject, Avg. Vel 2506

So my rifle consistantly will not eject the LC brass unless it is loaded at lower or near minimum loads, and even when it clears the ejection port, it still won't get the next round chambered. Strange, is it cause the brass is swelling too much and its just getting to big for the chamber? Is this what a FL resize die is suppose to fix? Sorry I don't know much about all the different die types. Thanks for all the input so far, I am glad we finally got a load to start working in this rifle.

 

[MEHavey]

I guess too that the higher charges are not igniting the powder properly due to the cases not being warm at all to the touch immediately after firing.

(1) I'm not surprised at that since cases which aren't ejected right away transfer most of their heat to the surrounding chamber metal while waiting for manual extraction.

(2) You still aren't up to "normal" match velocities (2,550-2,600fps) for the 175's. Kick it up some more till you hit 2600, then see if they fail to eject/chamber the next round. [That said, something still isn't quite right if the ~2500fps loads don't function. Have you greased the bolt/roller/recess area? [never hurts]

(3) Can you easily chamber a resized case (no power/primer/bullet)? Absent pulling the bolt apart to get rid of the extractor, can you hand feed a case to full battery/bolt rotation, then "rock it" back & forth a 1/4" in to see if the bolt recloses/rotates fully with no effort on your part? If it does, the sizer is doing its job. And is there a difference in this test between the LC and commercial cases? If there is a difference, and absent a small-base die to ensure the case base is under chamber size, set the LC's aside to use the commercial from now on.

LAST THOUGHT: If the rifle is partially-ejecting a fired case and slamming that same empty case back into the chamber, THAT CASE HAS UNDERGONE HIGH-PRESSURE EXPANSION DURING EVEN PARTIAL EJECTION. It's no surprise that such a (now) oversize case would "stick." [This is also consistant w/ the higher charges giving you "stickier" hand ejection, since the pressure/case expansion has increased.]

LAST LAST THOUGHT: Turn the gas cutoff selecter around 180 degrees.

 

[243winxb]

LC Brass Problem-Small Base Die Needed?

is it cause the brass is swelling too much and its just getting to big for the chamber? Is this what a FL resize die is suppose to fix?

What is the history of the LC brass? The web area is not sized by a standard full length sizing die. You may want to try a small base die. Take measurements of the web area of the brass. It should not be larger than .4703" Another possibility is you have a tight chamber. If the LC brass is defective, having a smaller then normal case capacity, pressure of a reload would be high, causing slow extraction of fired brass.Excess pressure will expand the web area. Brass fired in machine guns may have an expanded/oversize web area. Here is a drawing of the cartridge & chamber. http://www.saami.org/PubResources/CC_Drawings/Rifle/308%20Winchester.pdf

 

[243winxb]

COL- Make sure the bullets are not hitting the lands/rifling. This could raise pressure. About .020" off the rifling is good.

 

[lowlytech]

I don't know the history of the brass, it was aquired from a GB auction years ago. I did have it all sorted out to match by headstamp. I might try another headstamp for the heck of it and see if it behaves differently. I just used the LC 05 cause that is what over 2/3rd of the brass I have is. Tonight I think I will measure the back end of the cases. I have a gut feeling its going to be bigger than the commerical brass. I guess that means I am going to have to hunt down a Small base die. What is the generally accepted best brand of die for this application? Dropping a LC resized case in the chamber, it will fully seat and can remove it easy but I have resistance when I try to rotate it, the factory gold medal cartridge drops in, removes and freely spins while inserted.

 

[MEHavey]

If your brass will easily chamber & extract unfired, then you don't have a sizing problem. If you still want a small base die (and I actually use one out of habbit), then I suggest an RCBS.
http://www.midwayusa.com/viewProduct/?productnumber=597261

 

[A and O]

The problem is most likely the mag that you are using. When I first got my m1a I had a problem with the supplied mag and spent a lot of frustration figuring it out. Went through all the above until I bought some mags at a gun show. Worked flawlessly ever since. In comparing the mags it turned out the feed lips had been bent ever so slightly, almost could not tell except when beside a proper mag.

One other poster above had said he had the same problem. I would look here before going through all the trouble that I went through. Very frustrating, it appears the m1a is very picky on the angle of feed. Only a guess, but it worked for me.

Also, when buying military 308 brass I buy fully processed that has been roll sized for the reason being it has been fired through a mg.

Let us know what you determine and your fix.

KB