Marlin Lever Evolution SS 45-70 popping open

[Swede44mag]

I have a Marlin Evolution SS 45-70 that pops open (meaning the lever opens partially) when I shoot a charge of 49.2gr IMR 4198 with a 300gr RCBS RNFP with a gas check shot over a Crony at 2000fps
if I don’t hold the lever shut real tight.

The charge is listed in the Hornady 3rd edition on Page 301 but for a 300 gr jacketed bullet.
I have tried IMR 4198 powder at 1800fps with the same boolit and do not have the problem.
The shells don’t stick in the chamber at 2000fps and don’t have flattened primers.

Have any of you had the same problem or do you think there is something wrong with the lockup on this rifle.
I bought the rifle a couple years ago at a Gun Show as new so hopefully it is not one of the remlins I have been reading about.

[Gtek]

Swede, that load is approaching max. I have more than a couple 45-70's and a 450m. You are one gr. shy of max listed load. I have shot enough to know the feel and you are at the point of artillery.
Please take no offense, Are you sure your not doing it without realizing it? The s/n will tell you year of manuf. Plus circled JM on left side of barrel fwd of rec. Remlin's have REP on RH side. I assume your sure you are not landing bullet in forcing cone- COAL, crimping in cannelure usually keeps you out of trouble. Be Safe. Gtek

[Swede44mag]

I am crimping in the cannelure I plan on pulling all the loads that are hotter than 1800fps.

I have read a lot about people shooting at 2000fps some said I should be safe with this load. Any sugestions on a better/different powder I can use and still get good acuracy.

I put a Kick-eze magnum recoil pad on to control the recoil.
It use to make my arm black and blue but no more.

[W.R.Buchanan]

Swede: I consulted the Loading the .45-70 Marlin article by B Pearce in Aug 07 Handloader and you are no where close to max with that bullet.

His tables show 300gr Nosler Partitions at 2300fps with 55gr of H4198 which is close enough to IMR 4198 for simple comparison. This load is below 28K psi.

300gr Sierra at 2440fps with 58 gr of H4198 is below 35K psi. And these loads are well within the strength of the Marlin action as he lists loads in the 43K psi range also. Just None with 4198

Point of this is all of these afore mentioned bullets are jacketed and have much more resistance than your lead boolits do. IE pressures with your loads should be much lower than these.

I would highly recommend that you obtain a Aug 07 back issue of Handloader Magazine for this article as there is over 100 loads for these guns all the way from plinkers to elephant rounds, and at every socially accepted pressure range. it will be the best $10 you've spent on the .45-70 experience.

The cases won't stick in the chamber even if you blow the gun up, it is just one of the features of the .45-70's case design.

Something else is wrong.

Another thing you can look at, and this is covered in the rework instructions On Leverguns .com, is the combination trigger and lever safety spring. It is a hairpin spring that tensions the trigger and pushes the Lever safety down . You can bend it backwards to relieve some of it's pressure which will make the lever easier to hold closed. This little safety prevents the trigger being pulled with the lever partially open, or to put it differently the bolt locking lug not completely engaged and in Battery.

IF you can easily pop the lever open/out of battery with very little pressure this spring needs some attention. It also serves to reason that it would pop open under recoil. this spring works in concert with the lever Detent spring. This other spring is included in the Brownells reduced pressure spring kit. My gun would not keep the lever closed with the reduced pressure detent spring in as the other spring was too stiff. I couldn't use that spring so I had to remove it and put the original back in to hold the lever closed. I will revisit this later on as I don't like the way it works. My 1894 works perfectly with it installed but I tweeked the lever safety spring on it. I didn't do this on the 1895.

Without this excessive tension pushing down on the lever, the gun should stay closed and locked during firing unless you are seriously over pressuring it. I see this as an easily fixed mechanical problem, and not a load problem.

That's not to say your loads aren't "peppy" they just aren't dangerous.

Once again here is the direct links to the instructions on how to smooth out these actions. I can't get these links to stay active they worked earlier today. See my Marlin refinish thread for the working ones.

Fixing the Dreaded Marlin Jam
http://www.marauder.homestead.com/fi...rlin94Fix.html

Tuning Marlin Leveractions
http://www.marauder.homestead.com/fi...ING_M_1894.htm

Randy

[Swede44mag]

Randy:
If it matters I put a Wild West Trigger in to lower the trigger pull and make it smoother.
It seemed to help it was a quite heavy trigger before.

I dont know if it would have anything to do with it popping open but I thought I would mention it.

[W.R.Buchanan]

Swede: the spring I'm talking about is the trigger/ lever safety spring. the one piece trigger is not involved, just the other side of it's return spring.

The spring uses one side for the trigger and the other side pushes the little lever safety piece down. It must be compressed when the lever is all the way closed. Sometimes they can be a little stiff.

IF you go to the Tuning Marlins link I provided you can print out the instructions and see the section that deals with the little spring. You have to tweek it and and it is a trial and error type of process, but it is not hard at all.

Randy.

[Swede44mag]

Swede, that load is approaching max. I have more than a couple 45-70's and a 450m. You are one gr. shy of max listed load. I have shot enough to know the feel and you are at the point of artillery.
Please take no offense, Are you sure your not doing it without realizing it? The s/n will tell you year of manuf. Plus circled JM on left side of barrel fwd of rec. Remlin's have REP on RH side. I assume your sure you are not landing bullet in forcing cone- COAL, crimping in cannelure usually keeps you out of trouble. Be Safe. Gtek

I checked for the stampings you said and it's not a remlin thanks for clearing that up.

[gefiltephish]

Randy, your links aren't working (for me).

[Jailer]

Swede44mag you might want to check the finger lever plunger and see if it's binding. Mine was and I had to polish the hole in the lever that it slides in.

I was searching high and low for something to drive the finger lever plunger pin out of the lever when I was doing the action job on my Marlin. Just so happens I had a couple spare Lee universal de capping pins on my desk that I had ordered from Lee to have around as spares. The pistol de capping pin itself is a perfect fit to drive out the finger lever plunger pin and the large end is perfectly sized for polishing the hole in the lever that the finger lever plunger slides in.

I just used a small piece of scotch tape to hold a small strip of 600 grit on the de capping pin and just spun it with my fingers to smooth out the hole. If it wears out before you're done just trim about a 1/4 inch off the end of the paper and keep going. Polish just enough until the finger lever plunger slides smoothly in the hole.

The pins are $1.99 at midway.

http://www.midwayusa.com/Product/274540/lee-universal-depriming-and-decapping-die-pin

http://i19.photobucket.com/albums/b180/Jailer/posting%20pics/Leedecappingpin.jpg

[W.R.Buchanan]

Also on removing that pin note the pin comes out from Right to Left. It WILL NOT go thru as the pin has splines on the left end .

It must go back in left to right.

Randy

[Old Goat Keeper]

Another thing that may be happening is that with the faster load the recoil is enough more that your hand is not keeping after the lever when it recoils and unlatching it a bit. Try holding the lever in really tight when you shoot those loads.

T-o-m who also has one of those Thumpers

[35remington]

OGK may be right about recoil causing it. The gun goes backward while your hand, in the lever loop, stays still. This makes the lever "pop" open when it is really nothing to do with the load.

See if it pops open when your hand is around the bottom of the lever loop rather than inside it.

Pump guns "blow open" when shot the same way....inertia and recoil make the gun into a self ejecting type. Nothing wrong with the load. It's just recoil doing it.

[looseprojectile]

that the lever is not bent and hitting the lower tang before it locks up completely.
The previous owner may have bent it when forcing a too large cartridge to chamber.
Simple matter to bend it back.
I hope you find a problem that can be fixed easily.

Life is good