7.62x39 and IMR 4227

[tkcomer]

While waiting on my back ordered Model 1 upper to come in, I thought about trying to gather some data on loading for the 7.62x39. I have IMR 4227 on hand, CCI 200 and 250 primers. The load data is throwing me. The Hodgdon site only list one load for the IMR 4227. Maximum, and that's 18.5grs with a 125gr spire point bullet with a .311" diameter. No mention of what primer they used. My second edition Sierra book lists 20.6grs starting to a max of 24.3grs. But that is with their .308" spitzer bullet and a CCI 200 primer. That's a sizable spread. If I decide to load for this gun, I'll use the Hornady .310" 123gr FMJs. So does anyone use IMR 4227 with the Hornady bullets? If so, what load data are you using?

 

[brentwal]

Here's some data from a IMR guide dated 05/03

7.62 MM X 39
IMI CASE; CCI 200 PR
SPEER 125 GR. SP; .311 DIA.
20" BBL.; 2.180" C.O.L.
IMR 4227 18.5 1995 44100
IMR 4198 24.0 2250 42500

It's only showing max load no start load, same with Lee's reloading guide.

You might look into Accurate Arms 1680, it was designed for 7.62x39, and seems to be cheaper, at least around here.

AA1680 Load Data for 7.62x39

 

[tkcomer]

I'm not too sure I'll load for this caliber yet. Just thought if I put an order in to Midway, I might pick up some bullets and brass just to try it out. My Sierra book is old and doesn't list new powders like AA. Just spotted the 4227 data and I have that on hand. But then I spotted how much difference there was between Sierra's data and Hodgdon's site and began to wonder if the smaller diameter bullets Sierra was using was the reason they used so much more powder than the Hodgdon loads.

 

[Hoopie]

For what it's worth, that load of IMR4227 with sierra 125gr. .311 diameter wouldn't cycle the action in my SKS. I haven't found any bigger loads for that powder other than different people's personal hot loads. I now use H335 just shy of Lee's 2nd edition recomended max load. Works nice.

 

[tkcomer]

What load did you use? I don't think Sierra had that bullet when this book came out. They shot their 125gr .308 bullet out of a test gun that had a .312 barrel. The Model 1 barrels are .310. Does the SKS need more gas to cycle the action than the AR-15 type rifles? I did notice on the Hodgdon site, the 4227 load was way down on velocity. 1995fps with their max load. Sierra shows 2500fps with their max. Heck, their minimum is 2200fps. But Hodgdon doesn't mention what gun they are using. I need to locate data for a semi-auto gun. They may recommend against IMR 4227.

 

[jinxer3006]

Hodgdon Starting Loads

When you go to the reload data center on Hodgdon's website, you get the disclaimer screen. If you scroll down that screen, they have this to say about starting loads:

"For those loads listed where a starting load is not shown, start 10% below the suggested maximum load and then approach maximums carefully, watching for any sign of pressure (difficult extraction, cratered and flattened or blown primers, and unusual recoil). H110 and Winchester 296 loads should not be reduced more than 3%. "

So for the load listed 18.5 grs max - 10% = 16.65 grs starting load, so I would start @ 16.7 grs.

 

[res45]

I load several different combinations for the 7.62 x 39mm in my two SKS rifles. All data is form the Lyman #48 manual

Winchester cases
Standard LR Primer. I use the CCI#34 Mil-Spec primer/it is a MAGNUM PRIMER
Hornady .310 dia. 123 Gr. FMJ,SP,V-MAX

I use 25.5 Grs. of either AA1680 or Reloader #7 with either or these three bullets, and 24.0 Grs. even of IMR-4198.

Max loads for these three powders are.
25.7 Grs. AA1680
26.8 Grs. Reloader#7
24.6 Grs. IMR-4198

Load data for IMR-4227 using 123 Gr. bullets.
Start 20.0 Grs. Max 22.0 Grs.

This data from the manual is designed to be used with the standard LR primer,I use the CCI#34 to help eliminate the slamfire issue in my rifles because of the free floating firing pin issue and I worked my loads up accordingly.

 

[tkcomer]

res45. Your book actually uses the Hornady bullet. The 4227 data is more in line with the Sierra manual. Plus the 4198 in your book has a higher max than the Hodgdon site. In the Sierra book, they show a max of 26.3grs. Starting to think the Hodgdon site is very conservative. When I saw how much lower the load data was on the Hodgdon site was versus my Sierra book, I got worried. I'm not set on 4227. I just have it on hand sitting there. I went to another powder for my 44 mag when I swapped over to cast bullets. AA1680 and H335 are mentioned a lot when I do spot posts on loading the 7.62x39. But then again, I don't spot many posts on this caliber.

 

[res45]

In the Sierra book, they show a max of 26.3grs.

Is that for 4198,I bet that's a hot load.Personally I have loaded 26 Grs. even of AA1680 with the Hornady 123 Gr. bullets in my YUGO SKS it shot excellent but I did notice the primers were beginning to flatten somewhat so I backed off to 25.5 instead and that stopped. The loads I tested with RL-7 @ 25.5 Grs was very accurate in my YUGO and Chinese,I plan to testing that farther out towards the max load at some point but for now thats fine.

A couple of post you might be interested in reading.

http://www.sksboards.com/smf/index.php?topic=30961.0

http://www.sksboards.com/smf/index.php?topic=39057.0

http://www.sksboards.com/smf/index.php?topic=38404.0

 

[tkcomer]

Thanks for the info res45. Good shooting. You even showed bullets I didn't know they made. Which powder do you like the best so far? I don't have a gun shop around here. I have to drive a ways and hope they have what I want or UPS it in. Not sure how the AR-15 upper will treat the brass, or I should say, those copper washed steel cases yet. I'll find that out with the com bloc ammo I bought years ago. Glad to see you use Lee Pacesetter dies. Those are the ones I have in mind. I don't have the CCI #34 primers. I have a lot of the CCI 250 primers though. I just figure for about the same price, I can load better ammo. After I get my brass stocked up.

 

[res45]

AA1680 is especially made for the 7.62 x 39 its a ball powder it has good velocity,it's an accurate powder and meters well if you use a dumper,only problems I have with is that I can't get it around here and it a bit dirty. My personal favorite is Reloader #7, I can use it with 123,125 and 150 Gr bullets it's a short stick powder that loads well and it's clean burning.

I also like the IMR-4198 you can get about the same MV with less powder,it burns clean but it's a little rough going through a dumper and trickler. Once the AA is used up it will be my second powder of choice. I use the CCI #34 because of the slamfire issue,my YUGO and Chinese have free floating firing pins I don't know about an AR or if thats an issue with that or not so I can't say anything about your primer choice. PM sent.

 

[AgentAdam]

You know Murray makes a nice spring loaded firing pin conversion based off the original Russion design for the other SKS clones.

http://www.murraysguns.com/sksown.htm

I see people regularly at SKSSurvivors with blown primers even using the weak wolf ammo,and there firing pin usually bends and gets stuck in the bolt. Cant be to much fun.

If you are having ejection problems i would recommend a new over sized stainless steel gas valve.

The SKS does need allot of oomph to get the bolt back because the bolt and bolt carrier are rather large heavy. There is also a trick on using a paper clip bent in a circle as a gasket between the gas valve and gas piston tube.

 

[res45]

Adam those are all good points of info,I don't have one of the Murrays pins but I'm thinking of getting one as a backup just in case. The good thing is you can use standard primer with his pin although on some occasion when you use some of the commie ammo that has really hard mil-spec primers you may experience so FTF issues but a doubletap usually fixes that.

The wolf ammo did have a bad reputation for awhile with the primer deal,some we underpowered some loaded a little hot and still some of the problems weren't caused by the ammo at all it was a small ridge on the face of the bolt around the firing pin hole that cut a nice little roundout on the back of the primer that caused it to blow Murray has a fix for that also if you send him the bolt it part of the standard install of the firing pin process.

His gas valve is a little more expensive than the CNC and want allow you to switch the valve for semi-auto to single shot without the use of a torque tool he provides with the valve but thats no big deal it also slightly oversized to give you a little tighter fit than the CNC valve which is what I have and it has worked fine for years.

 

[steve4102]

Hey Tk, I think your second addition Sierra is ready for the bone yard. This is what Sierra # five has for the 125gr SP .308 fire from a Ruger mini-30
IMR 4227 20.5--23.0
H4198 23.5--25.5
IMR 4198 22.9--25.4

125gr SP .311
IMR 4227 20.6--23.0
IMR 4198 23.1--26.1

For what it's worth my Ruger Mini-30 will not cycle IMR 4227.

 

[tkcomer]

Yeah, my book is old. I see data that is way down from my book. Then again, I see data that is the same. I'm going to get the One Book/One Caliber booklet on my next order. I have those for other calibers. A lot of info packed into that one book.