Hi Everyone,
I have a question about reloading to M2 Ball specs for my M1.
I'm using Hornady 150 grain FMJBT with IMR 4895 and WLR primers with LC 69 and HXP 68-78 brass, all once fired. I've cleaned, de-primed, de-crimped, sized and trimmed the brass but I'm reading a lot of different reports about powder loads for IMR 4895. Various publications list loads ranging from 43 up to 46 grains with some saying to back out a few grains for military brass and other not making a distinction.
I don't want to go so low that the gas system doesn't cycle but I don't want to run too hot and risk beating up my op rod (it's uncut so I'd like to keep it around). My plan was to have a trial run of three clips of increasing loads starting at minimum load to see what works best in my rifle. Can anyone recommend a good starting load and what increments might work best?
Just use the starting load in your manual. Will function fine and easy on the workings.
Two M1s I have tested worked down to 34 grains H4895, so you have a way to go without worrying about lack of function. I chrono'd the starting load in my manual (42 gr, IIRC) and was 95% of the velocity of M2. Trajectory difference of 1 MOA at 500 yards, easy on the rifle and case.
SoM
I'd have to be at the house to look in my "book" for my load. I also have been using IMR4895 and pulled fmj's (lately I've been buying Hornady 150 grain fmjbt's but haven't shot any yet).
When you start shooting the lower powder loads look at the primers. Keep your brass segregated by powder amount and compare each increased powder amount to the ones prior - look at the primers. I still look at my primers (fired primers) and use them to determine when I'm getting too much powder = pressure.
Look at an unfired primer. See how the edges where the primer meets the primer pocket are nicely rounded (no question mark here, the edges have a nice radius, you'll see that). As pressure levels increase that nice rounded edge will decrease in size as the pressure pushes the primer metal down flatter against the bolt (sort of like mashing a balloon between your hand and a table top). I can't "tell" you how flat is too flat but you won't need a primer flattening load to get good accuracy. Good accuracy is usually obtained at less than maximum bullet velocity.
You can also look at the edges of the firing pin indentation in the primer. Sometimes this can be misleading if you have an enlarged firing pin hole in the bolt but you should still look at it. As pressure gets really high you can see the material of the primer start to raise up like the walls of a crater around the firing pin indentation in the primer. That's a sign of pressure pushing the primer metal back into the firing pin hole in the bolt around the tip of the firing pin. Don't go there. If you see that stop and don't keep shooting those loads.
If you're loads are "too light" you'll see the necks/shoulders of the brass are dirtier than normal. That means the pressure is not high enough to really expand the brass of the case well enough to seal the burning powder in the barrel and some of it flows back down around the neck and shoulders leaving a carbon deposit. My accurate load for my M1 Garand does this. The brass is pretty dirty but it shoots so good I don't care!!!! I can wash my fingers off when I'm done picking up brass and then run the brass through the brass polisher and smile about my group size (and the memory of wildman coming down the line to look my M1 over and ask me if it's got a match barrel on it 8) ;D).
Reducing powder depending on the brass headstamp seems to be (in my experience) more for .308 Win/7.62 Nato brass than for 30.06 brass. I've loaded HXP (the CMP Greek surplus brass) and commercial cases and even weighed them on the scale and don't see much difference in them. If you've resized and trimmed your cases any difference in weight is mostly due to differences in case wall thickness. Heavy brass = thicker case walls = less internal volume = higher pressures. It can make a difference when your near a maximum load already.
Start low (like SoM said) and work your way up and pick the most accurate load for your rifle. I'll get back later with mine from my logbook in the shed.
Thanks for the information guys! I really appreciate it!
I'm using IMR 4895 with Lake City brass, CCI BR primers, and either Hornady or Sierra 168 gr bullets. I started with 40 grains of 4895, and saw some signs of pressure in a relatively new M1A with a Match barrel - primers were a little flat. I had a few case separations that I later determined were due to the fact they were previously fired through a machine gun with a sloppy chamber.
Nonetheless, I backed off to 39 grains and am showing very tight groups out to 200 yards. Sniper brass solved the case separation problem, but I'm happy with the lighter load anyway. The way I see it, there's no reason to beat me and the rifle if its not necessary.
The spec for USGI brass is 200 grains, less 20 grains. So that is a 10% allowable difference in case weight for spec brass.
The primers are the worst indicator of pressure. Flattened primers can occur with loads that are perfectly safe. Cartridges that are full length resized, setting the shoulder back, can create effective excess head space. This will result in flattened primers every time. It will also lead to your case head separations and constant case trimming.
The better indicator would be to pull a USGI cartridge down. Use the USGI primer for your load and see what happens at the case head, just in front of the rim. Measure a case fired with the USGI load and one with your reload. This is a truer indication of excess pressure.
Do a search of the forum looking for "Hatcher's Notebook". Read up on head space and pressures.
The primer is not the best indicator of pressure. Hatcher's notebook is a great read. http://fliiby.com/file/34336/00e59nlpxm.html Hit full screen to view.
The Mil Spec for 168gn bullets is 42grns of 4895. I wanna say the M852 version. Sounds like it may be a sizing issue. Do you use a case gauge? That may lead you in the right direction. If you don't short cycle then less powder is cheaper anyway. ;) Just some random thoughts worth maybe 2 cents. Fill us in when you figure it out. Thanks.
I checked my book a little while ago.
In 30.06, military or civilian cases, I'm using 48 grains of IMR 4895 with 150 grain bullets. No signs of pressure. Necks/shoulders are a little dark/dirty like the neck isn't quite sealing well (low pressure???).
In .308 I am using different amounts of powder. 42.8 grains of IMR 4895 in civilian cases and 41.4 grains in military cases.
In 30.06 150Gr. I'm using 48.5Gr. IMR 4895
168Gr. I'm using 47.5Gr. IMR 4895
Quote from: Old Dog on July 11, 2010, 09:22:37 PM
In 30.06, military or civilian cases, I'm using 48 grains of IMR 4895 with 150 grain bullets. No signs of pressure. Necks/shoulders are a little dark/dirty like the neck isn't quite sealing well (low pressure???).
Do you set your bullet seating die so that it touches the shell holder?
The part of the die that crimps the case mouth contacts the case mouth before the die contacts the shell holder - I don't crimp so it sits up a little higher. I adjust the seating/crimping die down till it touches the case mouth and then back off part of a turn to make sure no crimping occurs.
The HXP brass (as the ammo comes from the CMP) does not show the dirty/blackened neck/shoulder area.
Quote from: Old Dog on July 12, 2010, 02:47:44 AM
The part of the die that crimps the case mouth contacts the case mouth before the die contacts the shell holder - I don't crimp so it sits up a little higher. I adjust the seating/crimping die down till it touches the case mouth and then back off part of a turn to make sure no crimping occurs.
The HXP brass (as the ammo comes from the CMP) does not show the dirty/blackened neck/shoulder area.
You are correct. Major brain f**t on my part. :-[
I meant to ask, does your sizing die hit the shell holder? :)
Yes. I'm reloading and putting the stuff in cans (need to buy more ammo cans) so it could end up in anyone of several M1's.
If I was reloading only for the one I shoot I would "play" with the sizing die adjustment as I did with my M1A and not completely/fully resize the brass so as to make it fit the Dec. 44 M1 chamber better (and increase brass life).
Exactly where I was going with the question.
I never FL resize. I set the die 1/2 to 3/4 turn above the shell holder. No need to set the shoulder back.
Doug, is that because of the generous chambers of the M1? Also, were the M1903 chambers cut a bit generous as well?
Nator
No. Actually the 1903 was held 0.002" tighter then the M1. The 1903 head space had the minimum set at 1.940", the M1 at 1.942", with both at 1.944" for new rifles. Both had a limit of 1.950" to send the rifle back for repair.
What backing off the sizing die does is leave the cartridge shoulder fire formed to your chamber. The helps prevent case head separations. If you set the shoulder back every time you size the die the case has to stretch every time you fire the cartridge. The firing pin will push the round tight against the shoulder of the chamber before it dents the primer enough to cause ignition. Any space between the breech face and the case is room that the case must stretch to fill as the pressure in the cartridge builds.
Set your dies 1/2 to 3/4 off the shell holder and the number of times and the amount you have to trim from your cases will be greatly reduced.
A little known fact, and one I catch a lot of grief over revealing, is that the ideal 30-06 cartridge is 0.005" longer then the ideal chamber! The case shoulder will be set back that much on cambering the round. I've reloaded for several M1s and they all feed cartridges resized as I describe without any issues.
Keep your powder dry.
Doug
Despite specs you get what you get. My M1A has a NM barrel on it (oooohhhh, everyone knows how tight and perfect NM stuff is, right) and I never full length resized the brass for it. I played with it by partially resizing it, attempting to easily/softly chamber it, put it back in the shell holder, turning the die down a partial turn and checking it again, repeat, repeat, repeat, until the cases would chamber while the op rod was slowly allowed to move forward from the pressure of the spring.
I never use the max load (in my experience with several rifles in different calibers) because the most accurate load is usually slower than max. fps.
A combination of only resizing enough to get the brass to fit your rifle's chamber and using less than max. loads will make your brass last longer.
Some rifles are "funny". I experimented with IMR4895 many years ago in my M1A and was not impressed. I bought one can, used some of it and moved on to other powders. Now my "shooter" M1 is a different thing. It seems to like IMR4895, so I'm using it for that.
Quote from: George63 on July 15, 2010, 08:14:27 PM
redding makes sets of shellholders that are oversized .002 - .01 so the shellholder still contacts the die and has the press cam over for consistantcy when sizing brass long
Since you don't touch the shoulder, there is no real difference. The resistance of resizing will be about the same. IHMO, it's one of those thing that solve a problem that did not exist. It might make some difference if you were loading match ammo.