powder blowback on a '92

[long colt lawrence]

Help!

My EMF 92 blows back a nasty powder residue with each shot. I've been cryin' about it since yesterday. Actually I took my first shot without my safety glasses on and it feels like weld slag on my retina. Anyway, the gas is going past the casing and the ejector configuration throws it right in my face. Anybody else experience this? I'm new to reloading and I guess I'm sizing them too small which lets gas around the shell -or- my load isn't powerfull enough to expand the case and seal it off.

Any suggestions?

thanks

[roberthonike]

Are you sure it is going around the casing? What do the primers look like? I can't imagine cases not expanding enough to seal in a normal chamber with any reasonable load. If you over sized the cases you would have a big bulge when you seat the bullet, but the cases should still seal.
If you have excess headspace it is possible to have the primer back out enought to leak, then, as pressure falls enough, case loses grip on chamber, moves back and reseats primer. Are you loading heavy enough to spring the action? Tell us more to work with.

[long colt lawrence]

Hey thanks roberthonike,

         I should've given more info. Here's the specifics:
45 LC,  unique powder  6-7.6 grains, 200 gr. roundnose.

The reason I say 6 to 7.6 grains is that the auto measure cavity holds 7.6 gr. weighed on my scale, but yesterday random tests showed it weighed +6 grains. I think this is because the powder is "flaky" and sometimes doesn't settle in the measure very dense (if that makes sense).

[roberthonike]

You have got to have more accurate measuring than that. I will use this for an example. A friend of mine was loading .223 with, as I remember, IMR 4320. I watched him run some loads, and all of a sudden, a whole bunch of powder poured out. I told him to go back and start pulling bullets and weighing charges, and he really did not want to, but he found he had a whole lot of almost uncharged cases, and some stuffed to the brim. You have got to consider a 1.6 grain variation unacceptable, and I would suggest pulling some bullets.  There are many situations where not enough powder is more dangerous than too much. You need also to visually inspect every case for powder level before you seat the bullet. and set aside one out of ten so you can go back every so often and weigh the charges.

[Mikey]

Long Colt:  That load you are using sounds a bit light to me.  In addition, as roberthorndike mentioned - you have to be more accurate than that.  

I would not be surprised if there are a couple of things causing your problems.  One might be a light load.  If your cases show something like a half moon powder burn going back from the case mouth you are getting some blowback from the loads.  I've seen this with light loads and target loads.  You may also have a headspace problem that will not permit proper chamber sealing and allows the gases to blowback at you.  Also, check your primers - if any of your primers are perforated that is an indication of an overcharge (although the maximum on your charge with the bullet listed doesn't immediately sound too high), and would also cause blowback.

This is a real good cause for safety glasses.

Please have a qualified gunsmith check your headspace.  If he says it is proper, or within tolerances, get some standard velocity/standard pressure factory loads and head back out to the range.  Take some sheets of plain white paper with you, or notebook paper or soemthing similar and some tape.  Before you sit down behind that rifle again, chamber a round in preparation to fire the rifle and tape a clean piece of paper over the action.  When you fire the round, if you still have gas blowback, this should tell you exactly where it is coming from, and then examine your fired casing for indications of blowback.  You may also have a sloppy chamber that may be too large to allow proper sealing of the case to the chamber walls.  Either type of an indication would cause me to take that rifle right back to the dealer for return and repair.

If, however, you do not have nay problems with the factory loaded ammunition, then I would surmise your problems lay with your reloaded ammo and you aare going to have to modify your practices to avoid more serious injuries.  

I sure hope this helps Long Colt - you be careful.  Mikey.

[long colt lawrence]

Thanks for the input gents,

I agree the variation is unacceptable. And I do have the halfmoon powder mark on the cases.  It bothers me that the variation exists at all.  I just got an bullet puller in the mail yesterday, looks like I'll be gettin' some use out of it.

[roberthonike]

I would check out some loads using 2400 powder. Always got good consistent drops with it. Also, use the knocker on the measure. Unique is sort of fast and touchy sometimes, not like Bullseye, but.

[Larry Gibson]

Long Colt Lawrence

My Rossi M92 in .45 colt does the same thing and I had the same problem with a M92 in .44 and a Winchester M94 in .44.  Headspace is not the problem, your loads are too light.  The pressure is not obturating the case to seal the chamber.  Either go to a heavier bullet or a faster powder like Bullseye.  I push a 200 gr cowboy bullet out of mine at 1180 fps (24" barrel) with Bullseye.  Any slower than that and I get blow back.  With 260 gr bullets I must use max loads for a Colt SAA when using Unique or I get blow back.

Larry Gibson

[John Y Cannuck]

I HAD the same problem with my original 1892, using Rel 7 Max loads.
Even factory loads were a bit dirty.
I learned that the action will with carefull load development take quite a bit more pressure. When the pressure increases, the case seals the gas nicely. The sudden pressure spike of Black powder works well here too.
Using a heavier bullet, or changing to a faster powder may also be a cure.
Remember, you are venturing into territory that the data lawyers will not like.
Be very very carefull.

This load worked very well for me. Now I must put in a very big
                          WARNING!

This load came from no loading manual, it is my own contrivance, it was developed by extrapolating data from other cartridges of similar case capacity, and is quite likely DOUBLE SAAMI PRESSURE SPECS.
I have limited experience with it so far, and have not checked it for accuracy, or chronographed it.

DO NOT USE IT IN A HANDGUN OR WEAK ACTION RIFLE!
Work up to it carefully in any other!

Pressure sign on low pressure cartridges is very difficult to read, and develops rapidly, go slow.

Winchester once fired case (38-40), 174 grain hard cast bullet, Winchester LR Primer, 23grains H110.

Note on H110. If you start very low, you may get hang fires, and misfires, and bullets lodged in the bore. H110 likes it hot.

REGARDLESS
 
BE CAREFULL, start low, go slow!

Hogdon does not support this load, and probably will warn sternly against it!

[JONAH]

Your loads ar too light for a straight case like the .45 Colt.  Go to a 250 gr. bullet and you will probably find it will solve your problem.  I fire 6.0 gr. Unique and 250 gr bullet and get no blow back.  With 200 gr bullet and the 6.0 gr Unique, I got blow back in my Marlin and my son got it in his Win. 73 clone.

[John Y Cannuck]

More info on the load above. I accuracy checked it today.    Sucked big time, wouldn't even stay on a three foot back board.  Chrono read 1758 fps.

[Charles/NM]

In my quite old Rossi 357 model 92 I use 8.0 grains of Unique under a 140 grain Remington HJHP and get very good accuracy and soft recoil.  That's the lightest load I've used.  Accuracy was not as good using either H-110 or AL-7 (yes it's old powder).  I got excellent accuracy with blistering hot loads using AA #9 and Rem 125 grain HJHP - I won't even mention the load because I think it would be too hot for my 3 screw Ruger Blackhawk, was in the 2000+  fps range in the rifle.  In short, at least in my rifle, fairly hot loads work best.
Charles/NM

[Blackhawk44]

Until you can hold your powder variation with that measure and Unique powder to about .2 grains or so, WEIGH YOUR CHARGES.  The majority of error in powder measures is the operator.  You must make every move with the same motion and amount of energy each and every time.  Take your time, this is a learned exercise.  But until your variation comes down, WEIGHT THEM.  With weighted charges, 8.5 to 9 grains of Unique would be much better for obturation of the case.