Marlin Spitting Blowback?

[Bronc]

My Marlin .45 is spitting blowback. Current load is 4.7 Trail Boss w/ 200 gr. bullet. This load works well in all my other guns. Maybe a faster burning powder. I would like to stick with the 200 gr. bullet. Any suggestions from those who experienced the same issue.

 

Thank

[Major Bill]

I am running 5.1 with TB on 200g bullet in a ‘73

[Garrison Joe, SASS #60708]

Marlin made a lot of those 1894's with VERY large chambers.  Got a shooting pard with one that does the same.

 

Some of the common ways to reduce blowback in .45 Colt rifles, with the most chance of success listed first:

 

Increase bullet weight to 250 grains (I know, you don't want to do that)

 

Increase chamber pressure (powder charge) to get the standard case to fill the chamber upon firing (I know, you don't want to do that)

 

Crimp tightly - which increases chamber pressure a little and makes case expansion happen quicker

 

Use the Redding 2-sizing-ring sizer die.   This keeps the bottom 2/3 of the case at large diameter, and only the neck is sized to better hold the slug.   Leaves a slight waist to the loaded round.   I switched my pard and my own loading dies to use that (expensive) Redding dual-ring die.  As a side benefit, I haven't split a .45 Colt case since I switched to this sizing die 16 months ago!  Before then, about 2 cases per hundred shot. (My favorite method, actually)

 

Anneal case mouths (top 1/4 of the .45 Colt case) to soften the brass and let a low pressure load seal the chamber better

 

Increase bullet diameter you are loading another thousandth of an inch or even 3 thousandths if you use a soft (Brinnell hardness 8) bullet - this raises chamber pressure without having to put in more powder!  (My second favorite method)

 

Use .44-40 cases and expand them to let you seat .45 Colt bullets.  Gives you a strange looking waist on the case just below bullet, but the much thinner walls of .44-40 will expand to fill chamber at lower pressures

 

Faster powder can do a little for  you.   But, there's not much gain, perhaps a little more is possible than usual since you are now using TB (a fairly slow pistol powder).

 

Reline your rifle barrel and have a "minimum" chamber cut in the new liner  (OUCH!)

 

Good luck, GJ

[Bronc]

Thanks Joe.

[Keystone, SASS # 47578]

Garrison Joe, thanks for your post. I have a fair amount of blow-by in 45 Colt cartridges in my 73. I have stepped my load up and maintain a good crimp. I use Lee dies and have been told their resizing/de-prime die is overkill on sizing. Would a different manufactures die resize less? Is it really necessary to resize rifle brass when shooting cartridges in the same rifle? 

Hasta Luego, Keystone

 

PS I tried a Marlin but couldn't adjust to it and was put off by the blow-by, in the face.

[Beartrap SASS#57175]

Try using Winchester brass, as it's thinner and softer than my usual favorite (Starline) or Remmington, etc.

It will seal better and annealing will make it seal even better.

Common perception is that BP shooters prefer 44-40 cases because of the bottleneck design to reduce blow by, but 44-40 cases actually reduce it because the cases are much thinner than 45 Colt cases and expand better.

[Charlie Plasters, SASS#60943]

10 hours ago, Garrison Joe, SASS #60708 said:

Marlin made a lot of those 1894's with VERY large chambers.  Got a shooting pard with one that does the same.

 

Some of the common ways to reduce blowback in .45 Colt rifles, with the most chance of success listed first:

 

Increase bullet weight to 250 grains (I know, you don't want to do that)

 

Increase chamber pressure (powder charge) to get the standard case to fill the chamber upon firing (I know, you don't want to do that)

 

Crimp tightly - which increases chamber pressure a little and makes case expansion happen quicker

 

Use the Redding 2-sizing-ring sizer die.   This keeps the bottom 2/3 of the case at large diameter, and only the neck is sized to better hold the slug.   Leaves a slight waist to the loaded round.   I switched my pard and my own loading dies to use that (expensive) Redding dual-ring die.  As a side benefit, I haven't split a .45 Colt case since I switched to this sizing die 16 months ago!  Before then, about 2 cases per hundred shot. (My favorite method, actually)

 

Anneal case mouths (top 1/4 of the .45 Colt case) to soften the brass and let a low pressure load seal the chamber better

 

Increase bullet diameter you are loading another thousandth of an inch or even 3 thousandths if you use a soft (Brinnell hardness 8) bullet - this raises chamber pressure without having to put in more powder!  (My second favorite method)

 

Use .44-40 cases and expand them to let you seat .45 Colt bullets.  Gives you a strange looking waist on the case just below bullet, but the much thinner walls of .44-40 will expand to fill chamber at lower pressures

 

Faster powder can do a little for  you.   But, there's not much gain, perhaps a little more is possible than usual since you are now using TB (a fairly slow pistol powder).

 

Reline your rifle barrel and have a "minimum" chamber cut in the new liner  (OUCH!)

 

Good luck, GJ

What's the process for annealing cases?

[Garrison Joe, SASS #60708]

Any good loading manual shows how case annealing is done. 

 

Simple way - stand cases in a tray filled with water half-way up the case.   Run a propane torch in a dark room over the mouth area until a case just barely turns red.   Tip case over in water and move on to next one.  If you take brass up to a bright red it will be so soft as to be worthless.   If you soften the head (rim and lower case) you also ruin the case.

 

Every time you load a case, you add work hardening to the brass.   Minimize the amount of diameter change on the mouth and you don't work harden that area so much.

 

You can also buy a $3000 machine that automates case annealing.  

 

Good luck, GJ

[Garrison Joe, SASS #60708]

Quote

Would a different manufactures die resize less?

 

That Redding dual-sizing ring die does resize less!  Pay more for it, and it resizes less of the case.  What a deal! 

[Cheyenne Ranger, 48747L]

24 minutes ago, Garrison Joe, SASS #60708 said:

 . . . You can also buy a $3000 machine that automates case annealing.  

 

I built mine for about $150.  check on cast boolits for ideas

 

 

[The Original Lumpy Gritz]

Up the load to 5.0gn, and use a firm roll crimp.

OLG

[The Original Lumpy Gritz]

2 hours ago, Garrison Joe, SASS #60708 said:

 

That Redding dual-sizing ring die does resize less!  Pay more for it, and it resizes less of the case.  What a deal! 

It does a great job!

OLG

[Dirty Low Down sass 23492]

Fought that blowback problem in my Marlin .45----tried all sorts o fixes------settled on 250 gr bullet --no more blowback----no big difference in shooting (recoil etc)------problem solved!!!

[Bramble Mountain Buzzard]

I went the other way than most here. I dropped the load a bit (3.5 IIRC) and then filled the case mostly full with filler. Corn media for me. (14 grains IIRC) Others will use cream of wheat. I get zero blowback. and almost no recoil using a 200 grain bullet.

[Dutch Wheeler]

Using fillers over smokeless powder is NOT a safe recommend practice.

[Garrison Joe, SASS #60708]

The only reason that fillers over the powder will solve blowback is that it RAISES CHAMBER PRESSURE.  By how much?  Enough to stop blowback, but is that increase giving a safe pressure?  We've seen reports of some cereal type fillers that set up real hard over several months and REALLY escalate pressures. 

 

Fillers are going where no powder manufacturer now recommends folks go with their smokeless loads!

 

Good luck, GJ

[Dutch Wheeler]

If you want to use fillers in your cartridges, load-up and shoot the Real Holy Black! 

With real Black Powder, you do not want any air space in the cartridge, so fillers are perfectly safe in that application for reduced loads.