.308 Reload question

[LlanoEstacado]

I am trying to work up a hunting load for my .308. Components are:
1. once fired brass from military surplus ammo I have fired
2. Barnes 165 gr. TSX BTHP
3. CCI Large Rifle primers
4. H4895 powder

It was hard for me to find data for the TSX - I finally located a Barnes reloading Manual. It suggested a little over 40 grains of H4895 for a starting load. I loaded some at 40 grains. The first round would not eject. When I got home, I opened the bolt and tapped it with a rubber mallet, extracting/ejecting the spent case. Primer showed pressure signs (cupped) and every dimension I could measure on the case was a little larger than the spent mil-surp ammo.

OK. Obvious too much pressure. The case does not show any splits/signs of head separation. the neck is indented on opposing sides at the end, rounded normally the rest of the neck.

Question: Where to I go from here? I was thinking of backing off 2 or 2 1/2 grains and see how that works. I am assuming the mil-surp is the reason for the higher pressure (thicker walls, less case capacity). Does that approach sound reasonable?

 

[coloradokevin]

Hmmm... I'll be interested to see what others have to say on this issue, since I don't really know the answer to your question.

I'd also speculate that the military brass case volume might have impacted your pressure, but that might not be the only factor. How deep did you seat your bullet? Were the primers used the ones recommended in the load data (I vary quite a bit on primers myself, but the last Barnes TSX data I loaded for in 8mm Mauser called for Federal primers)?

Incidentally, I'll bet you're glad you did the prudent thing while loading, and didn't try to start at the max loads!

 

[TonyAngel]

I'm really not trying to open a can of worms here, but I have read that military .308 brass does not have the internal capacity of commercial .308 brass and that you should reduce loads to compensate. I know that this issue is a bunch of hooey with regard to .223/5.56 cases, but from what I understand it is a real issue with .308.

I'd imagine that someone that is in the know will chime in soon.

Personally, I've been using Winchester brass. A bolt gun being so unlike an AR, I'm only doing around 150 rounds of .308 in a range session. At that low rate, the cost of the brass doesn't bother me.

 

[kludge]

http://www.barnesbullets.com/information/load-data/data308/
Sorry no data for 165gr and H4895, and Barnes bullets being less dense then is going to take up more space in the case than a typical 165gr. The good thing about H4895 is that is will burn at reduced load densities, and you can safely reduce the load to 60%.

Yes, absolutely reduce loads in military brass by 1 to 2 grains. This is recommended in the manuals I have read. Example: http://www.6mmbr.citymaker.com/f/Sierra308Win.pdf

If you got a stuck case, that's just not overpressure, that's WAY overpressure. And on a start load, that's scary, because the max load is going to be ~44gr with a 40gr start load, so reducing 2gr for military cases 40gr should still be safe. You may have other issues:

the neck is indented on opposing sides at the end

The very next thing you should do is measure your brass and trim it to the proper length AFTER resizing it. If your cases are too long (from what I quoted that seems to be quite possible) that could be the reason for overpressure. Also your bullets could be jammed into the rifling and you need to adjust seating depth.

40.0gr grains start load seems reasonable. Hodgdon lists 40gr as the start load for a 200gr SFT SP, but since you have had one bad experience I would reduce the start load another 10% (will be safe with H4895) and start at 36gr.

 

[LlanoEstacado]

Thanks for the unput. I did not pay much attention to the brand of primers, did not think that would make a big difference but will keep that in mind. I did check the brass prior to reloading, it was well within specs for length. As for OAL, I set that .001 under the published OAL limit.

Glad to hear it is safe with H4895 to back off...I'm a newbie and NO WAY would I have started off with the recommended max load...I definately see why manuals recommend not doing that now!

I think I'll start at 37.5 grains and see what that does after I pull a few bullets.

I'm not sure how to judge seating depth...I thought it a good idea to be just under the recommended length. I could not find any info on how to measure seating depth, so, if anybody knows any references/links that would be greatly appreciated.

 

[Mags]

I loaded 168 grain tipped TSX bullets 35 grains of RL15 for a start load working up to 39.5 grains with no pressure signs and a 2.8 OAL.

Granted H4895 is a stick powder and higher on the burn rate chart over RL15.

I am curious though as to what OAL you used and if maybe you mixed data up for IMR4895 and H4895.

 

[Dave P]

Obvious too much pressure.

Not nessesarily.


Did you full-length resize each case? You should.

And then did you each one drop into the chamber with no binding? They should.

A case gage is a very useful and cheap tool to have.

40 grains should be fine, I say.

 

[243winxb]

Barnes TSX BTHP - 308 Win.

http://www.barnesbullets.com/wp-content/uploads/2007/02/308WinWeb.pdf You should start with a bullet jump of .050" off the leade/rifling. This will reduce starting pressure.

Ty’s Tips

Question: I am attempting to determine an accurate cartridge-base-to-ogive length for the 140-grain TSX. I used a Hornady O.A.L. (overall length) gauge with comparator. My ogive-to-base length minus 0.050 inch is 2.647 inches. With this length, true O.A.L. is 3.155 inches with the bullet seated to the bottom groove. Is this a problem? One source said it is not. What do you say? With the bullet seated to 3.065 inches, ogive-to-base O.A.L. is 2.557 inches. I’m using a Ruger No. 1 chambered for the 7×57mm Mauser, so magazine length is not an issue.

Is it okay to load longer than the O.A.L of 3.065 inches listed in the Barnes manual ?

—Don Armentrout




Answer: Since your rifle doesn’t have a magazine, you are not limited in that regard. We recommend seating .050 inch from the lands for best accuracy, so seating to a true OAL of 3.155 inches is a great place to start, since that puts you at .050 inch from the rifling. This depth can be adjusted shallower or deeper in .010-inch increments until you find the “sweet spot” for your particular rifle.

Pay no attention to where the grooves fall. They are there simply to reduce the bullet’s bearing surface and provide copper displaced by the lands someplace to go. There isn’t an issue if you have a groove—or even two grooves—showing. Yes, you can seat these bullets longer than the Barnes manual shows (which is the SAAMI maximum specification) to accommodate your rifle’s chamber dimensions. Manufacturers are limited to the SAAMI spec, but as a handloader you can step outside the box and tailor the load to your rifle.

Use the 180gr data on there website for your choice of powder. i would have guess you data would have been OK, and not over pressure. A solid copper bullet will make more pressure than a lead core bullet of the same weight/shape. Brass can make a difference. http://www.6mmbr.com/308Win.html

The most important thing to remember about military brass is that the internal capacity will probably be less than commercial .308 Win brass, because military brass often has thicker webs or casewalls.

 

[243winxb]

How to find seating depth/COL and more http://www.brownells.com/.aspx/lid=12897/GunTechdetail/Gauging_Success___Minimum_Headspace_and_Maximum_COL A loaded rounds neck diameter should not measure larger than .343" Don't forget to trim your brass for length also.

 

[USSR]

You may have other issues:

Quote:
the neck is indented on opposing sides at the end

The very next thing you should do is measure your brass and trim it to the proper length AFTER resizing it. If your cases are too long (from what I quoted that seems to be quite possible) that could be the reason for overpressure. Also your bullets could be jammed into the rifling and you need to adjust seating depth.

40.0gr grains start load seems reasonable. Hodgdon lists 40gr as the start load for a 200gr SFT SP, but since you have had one bad experience I would reduce the start load another 10% (will be safe with H4895) and start at 36gr.

I agree with kludge's assessment. 40 grains of 4895 in and of it's self should not put you in a high pressure situation. However, if your brass OAL is too long and your necks are being jammed into the leade, THAT will raise pressures dramatically.

Don

 

[kludge]

OK, here is a drawing of a .308.

http://www.accuratepowder.com/data/...l(7.82mm)/308 Winchester Pages 260 to 262.pdf

Measure yours. Pay particular attention to max case length, COL, and neck diameter with the bullet seated.

Also, bolt action, semi-auto?

btw, great link, 243winxb, explains everything with detail and pictures!

 

[LlanoEstacado]

1. Case length under 2.005, but I will recheck.
2. COAL = 2.809 (listed on load data is 2.810)
3. I will have to check neck diameter. Unfired reloads did go into bolt action chamber easily and extracted easily.

I did neck size only as rounds will only go through my bolt action Savage and were once fired in that rifle sans problems.

I'll also double check that the data is for H4895 and not IMR4895.

I also thought of checking for load compression since the case has less capacity and I did seat bullet .001 under recommended COAL. I'm thinking I could do that by putting powder charge in unsized case and see what COAL is where bullet touches powder?

If none of the above seems out of order, I'll go ahead and reduce charge to 36 grains and try again, unless I missed something somebody points out.

The links about fine tuning the clearance to leades will be helpful no matter what.

Any comments welcome, I appreciate the input!

 

[kludge]

I don't think 0.001" is an issue. Some dies won't even hold that tolerance. My Savage 110FP .308 chamber has adequate room to load 168gr SMK at 2.900" ~0.015" off the lands.

To your point, I always check to see how high various charges come, particulary the start and max loads, and also noting how much powder it takes to get to the bottom of the neck, since anything above that will get compresses, usually, depending on bullet length.

 

[Maj Dad]

Based on my personal experience, I will NEVER load a military case over the starting load, whether fired by me or Joe S**t The Ragman at Camp Swampy. I won't belabor the issue, but I did exactly as you did and had to beat the bolt open with a piece of 2x4. I learned a hard lesson the easy way, and God granted me the continued used my hands & eyes...

 

[TonyAngel]

I don't know. I only recently started reloading .308, but to me, I don't think that you can shoot .308 in enough volume to justify the cost savings of going with military brass rather than a good commercial brand.

 

[GW Staar]

Based on my personal experience, I will NEVER load a military case over the starting load, whether fired by me or Joe S**t The Ragman at Camp Swampy. I won't belabor the issue, but I did exactly as you did and had to beat the bolt open with a piece of 2x4. I learned a hard lesson the easy way, and God granted me the continued used my hands & eyes...

What's more, is that Sierra's loading manual says to start at 1 or 2 grains below the starting load, when using military brass.

I don't know. I only recently started reloading .308, but to me, I don't think that you can shoot .308 in enough volume to justify the cost savings of going with military brass rather than a good commercial brand.

You obviously don't own an AR-10 or clone. With that action, the recoil is so mild that I have no trouble shooting the hell out of my R-25 Remington, and I have a great time doing it. I'm very thankful for the thousands of LC cases I was able to procure from a national guard rifle range 20 years ago. Saved them for this great rifle, luckily!

 

[LlanoEstacado]

Follow up: measurements

Here are the numbers on the rounds I handloaded:
1. COAL = 2.809 - 2.810
2. Sized Case length = 2.010
3. Loaded round neck diameter = 0.430 (measured at end of neck)

These are all within specs. I try measuring where the leades are by using the rifle's bolt to "press" a bullet into the case by chambering a dummy round with the bullet about 3/16" longer than the loaded cartridge. When I measured the result, it was 0.048" longer than the loaded round, which would be close to the recommended gap of 0.05 Barnes recommends. Since I could push the bullet into the neck by hand, I don't think there was enough force to push the bullet into the rifling. Of course, this is not the recommended way to measure but does demonstrate that the loaded bullet is not engaging the rifling at the current COAL.

I also measured the spent cartridge from the mishap and at 2.011, it is only .001 longer than the sized case length and is still in spec.

To recheck for compression, I looked at the level of 40 grains in a sized case and its level is well below the neck and taper, so compression does not seem to be an issue.

I am concluding that the problem then is simply the case capacity and am going to try and work up loads from 36 grains.

Again, thanks for the input. I have learned a lot and am thankful that no damage occurred from the load. I was aware of the pressure issue, but my Lyman book only mentioned backing off the maximum load, not the starting load. I did think about backing off it also, but had in mind the cautions about the risk of pressure problems from going below starting loads and chose not to. I guess my only remaining question is how do you judge that by powder type, as Kludge did?

 

[243winxb]

My Guess -Has to be the Military Brass?

my Lyman book only mentioned backing off the maximum load, not the starting load.

Did Lyman list a load for a Barnes TSX BTHP all copper bullet? Copper may make more pressure than lead core,even today. The grooves cut in Barnes bullets is there for a reason, to reduce pressure and fouling. Check the history of Barnes copper bullet. http://www.barnesbullets.com/information/product-news/publication-mentions/heavyweight-hitters/ The original bullet produced excess pressure when using loading data for normal lead core bullets.

Getting acceptance for the bullet was tough. It was just too radical a design and people wouldn’t give it a chance. As with any new product, it went though an evolutionary process. There were some problems early on with high pressure and with barrel fouling. The technological evolutionary process eliminated or vastly reduced those problems over the years, but it was a struggle to recover from the damaged reputation. Randy was persistent and he worked hard to get the bullets into the hands of some world-traveled big game hunters. The performance was too good to ignore and word spread. The X-Bullet soon became a favorite bullet for serious big game hunters because it would penetrate deep and track straight on big game while creating a large wound channel. It has often been said that the introduction of the X-bullet changed the rules, that it acts like a heavier bullet than it is.

Key words "vastly reduced" Reducing the powder charge will fix the problem i would guess. Make note that people loading at maximum (not you) have changed brands of bullets, being of the same type, weight, but with longer bearing surfaces with the results being high pressures. You should do a test using win,rem brass instead of the brass from military surplus ammo, then you might find the answer to the high pressures. Barnes load data for 180gr list a starting at 38.0grs of H4895. Has to be the military brass

 

[amlevin]

Here is a nice starting resource:

http://kwk.us/powley.html

Start by weighing your empty case, then weigh it filled with water. Use the net weight for "case capacity" in this computer. (Full weight minus empty weight).

Fill in the remaining variables and it will give you a good starting point.

I had the same issue with some military .308 brass and I found I had to reduce the charge by a considerable amount. While the Powley calculator shows results for IMR powders, you can use to see what reduction will be necessary by comparing with published loads for other powders.

For the brass I was using, I had to reduce my Varget loads by a full 4 grains, exactly 10% to yield the same pressure indications as my Winchester brass. Something else to consider, lower charges will also yield lower velocities. I have reserved my military brass for just "plinking' chores now and load Winchester or Lapua for long distance accuracy.

 

[LlanoEstacado]

amlevin, thanks for the link. That sounds much better than my eyeball method.

Regarding your comment about military brass in .308 for hunting, I've come to the same conclusion after I started looking at the numbers the lighter loads were likely to yield. Looks like the velocity at 100 yards might be marginal for reliable expansion and energy with those loads. I may just buy a box of factory loads for this season and use that brass next year.