GAs felt firing Springfield 1903 ?

[dogdoc]

I have a 1903 that i have fired with full power loads with no problems what so ever.A couple of days ago I fired some cast 170 grain bullets with 16 grains of 2400. On some rounds i could feel some gas blowback hit my face. Not enough to hurt but some "wind". The cases and primers were all normal with signs of pressure. There was some evidence of neck and case smoking on some cases. Could the pressure be too low to seal the chamber? Any ideas. I will check headspace but no problems will full loads. Thanks

Sonny

[Char-Gar]

Back about 1961 was shooting some old pre-WWII Remington match ammo off the bench in my 03. One shot did not feel right and when I looked at the rifle there was a wisp of smoke coming from the action. I also noticed the rifle was fully cocked. I extracted the case and found a burned through hole about half way up the case body. The gas had come back through the bolt with enough force to blow the cocking piece back to full cock. There was no damage done to either the rifle or me.

This story is to say that gas can come back through amd around an 03 bolt and be felt by the shooter. I would guess your thinking on this issue is accurate and very plausable based on my experience.

[StarMetal]

What you surmised sounds right. Another thing to look at is that the brass may be brittle and need annealed. In other words the brass has worked hardened and not expanded out to make a good seal. One more thing is if you're not using a filler you might have fired some of the rounds with the 2400 back against the flash hole and some rounds where the powder moved forward in the case. You will get different ignition from that. That might explain why just some of the rounds you fired gave a whisp of gas back through the bolt and didn't expand the case. If you don't wish to use a filler just tip your rifle upward to settle the powder back against the flash hole if your range permits you to do such an act.

Joe

[NVcurmudgeon]

dogdoc, Your report is about my favorite rifle and load. I have fired literally thousands of loads of 16.0 gr. 2400 in my NRA Springfield Sporter. Nearly all used 190-200 gr. boolits. Am I getting higher pressure with the longer, heavier boolits? I have no idea. I do use CCI 250 or Winchester LRM primers nearly always, on the (yet untested) theory that a Magnum primer will more surely find every kernel of the powder wherever it is in the case, and without fillers or elevating the muzzle before firing. Is this a new can of 2400? Maybe a slower lot? I never noticed any variation in lots of 2400. Today's Alliant 2400 is alleged to be FASTER burning than the old Hercules 2400. In your shoes I would try Magnum primers and/or a small increase in the charge. Even with 200 gr. cast boolits, and up to 24 gr. 2400 there were no high pressure signs.

[carpetman]

dogdoc--I think you identified your problem. Too light a charge. You are using a 170 grain bullet and NVCurmudgeon is using a 200 grainer which would allow him a lesser charge. Lyman does list 20.0 grain starter. Certainly wouldn't suspect over pressure,so I'd kick it to 20.0 and see what happens there.

[rvpilot76]

I too have a 1903A3 Springfield. I would like to start casting bullets for it and use a more "economical" loading for it. Where are you guys getting load data for the '06 using 2400?

Kevin

[Patrick L]

FWIW, my match load with 193 gr bullets is 18 gr of 2400. Absolutely no blowback in about 5 yrs and several thousand of these loads.

[NVcurmudgeon]

rvpilot76, Several articles by C.E. Harris, in which he recommends 16.0 gr. 2400 and a cast bullet of medium to heavy weight for the caliber as the go to load for most modern milsurp bolt rifles, and old Lyman manuals.

River pilot or recreational vehicle pilot? Either would make me nervous!

[rvpilot76]

Two seat, experimental, aerobatic aircraft with a 210MPH cruise. Beat that, Cessna!

www.vansaircraft.com

Kevin

[carpetman]

RVPilot---Lyman Manuals have loading data for 30-06 using 2400.

[dogdoc]

I miked some cases from the 16 grain 2400 cast bullet load and compared them to rem factory 165 grain fired cases. The necks on the cases from the cast bullet load were 10 thousanths smaller (.010). I would guess I was not getting a good seal ?

[Newtire]

Had a batch of military RA 43 that gave me the same symptoms in my Springfield. I got a "J-split" case. I pulled a couple of bullets & fired a light cast load using the unfired case & got the same little hole about halfway up. My guess is that brass of mine was too brittle. Sprayed little brass bits alongside of my face. Same thing, headspace OK & no problems since. I never thought of the reduced load doing that but sounds like that might be the thing alright.

[drinks]

Personally, if there is much smoking-soot on the neck and shoulder, I either up the charge or the bullet weight.

[Bob S]

Loads as light as 14 grains of 2400 with a nominal 170 grain bullet (311291) should obturate properly with good cases in a "normal" dimension 30-06 chamber. A WW II barrel could have an oversized throat and chamber neck area, or an older barrel could have excessive throat errosion. Either condition will not give enough resistence to the bullet as it leaves the case neck to allow the powder to develop normal pressure and expand the neck to seal the bore. Brittle brass could also contribute. I have found that most 03 and 03A3's do best with bullets sized to .311 or even .312, with the case necks expanded with a .311 expander to accept them (I use my trusty Ideal 310 tool, but the Lyman 31 Long "M" die will work fine). The necks are then "partially pre-expanded" and will make blow-back less likely, as will anealing the case necks. If you are unable to get your bullets to engrave on chambering, seating the bullets deeper will also lessen the likelyhood of blow-back.

Resp'y,
Bob S.

[floodgate]

Chargar and Newtire:

Those failures with old RA and earlier '06 loads - I had several with WW II RA 42's - were discussed a year or so ago on one of the earlier boards, and Linstrum came up with "de-zincification" as the explanation, at least if there is a coppery color around the opening. If I understood him corectly, this results from an electrolytic reaction in the presence of iron (like from old staples in recycled paper used in military packaging) and moisture; this eats the 35% or so of zinc out of the brass alloy, leaving a weakened lattice of the 65% copper component. The result is a "blowout" of the damaged case metal at that point. Maybe Linstrum wil expand on this, or correct me if I misunderstood. floodgate