Or in the case causes of hard lever operation.

Are there any other causes than high pressure that would cause a lever action rifle to be very hard to open?

Background, I have put a fair number around 100 rounds through this rifle using trailboss and H4227 with no problems what so ever.

I obtaine a load from a third party, published, but not by a major reloading, powder or bullet manufacturer.

I ran the load through quickload and it looked fine, around 18000psi (as far as I know the action and this cartridge has been proofed to 64000psi, so a huge margin for error????

I wanted to reduce the load in order to achieve a desired velocity, reduce recoil and minimise or prevent leading. So I tested some loads at load and -1 through to - 5.5 (5 of each) all seemed to work fine, all hit an 8" target area at 100 yards. There were no signs of pressure, all primers looked normal and no extraction issues!

I took the same rifle back to the range two days later, with 20 of the most promising load loaded. The first two shoots missed the target and were around a foot wide of the same, extraction and primers were normal. The third shot missed by the same margin, I couldn't open the lever at first, I waited 2-3 minutes and then with a hell of a lot of effort it opened. The case looked normal, the primer looked normal. I fed the empty case back into the rifle it slipped in fine and then extracted fine? I then tried it again, same thing, again, on the forth chambering inj went in fine, but took a lot of effort to extract (I assume this was the same orientation as upon firing).

What happened? When I say effort I mean a serious amount (though no tools were required). I can only assume a pressure spike?

The powder in question is fast, double base and extruded (N110)
The cartridge a 375W.
The projectile 379-250 LEE.
Cases winchester 3rd firing.

It may not be the powder to blame as there is one other factor, I slugged my bore at .376" and have been using the bullets unsized at .379" (I have order a .377" die but the post is letting me down on this item). Whilst .003" over bore is a touch too much this doesn't explain the 125ish rounds success before number 126. Was it a pressure spike due to a reduction in the powder or did the bullet stick for a 1/2 ms before moving on?

I have been reloading cast for a while now, but until recently I had always exclusively taken my reloading data from Lyman or Hodgdon (ADI) as I was exclusively using their powders (I am in no way blaming VV powders). I did however step in to uncharted territory and in doing so may have invited unecessary risk!

Is this a phenomenon likely to repeat itsels, am I trying to push too big a bullet with to little powder?

Have I been stupid?

Yes its probably to litte amount of to fast powder what cause pressure spikes.

To answer the question simply disregarding pressure: it can result from a purely mechanical issue......... eg

Dirty cases in a dirty chamber.

---> Brass build up in chamber <---

Neck sizing only can cause this as well.

Question.....why the heck are you using N110 in the 375 Winchester? Sounds like you're asking for a pressure excursion.

Also, check the sides of the case.....you may be getting fouling from low pressure blow-by.

I use the same bullet, unsized Lyman #2 alloy, over 8 gns of Unique. It's a very easy on the shoulder and accurate load.

I saw it listed as a reduced load powder in a German manual, it is listed in cases from the 22 hornet to the 45-70. It seems in Europe these use it instead of 2400!

Alliant powders are hard to come by in Australia, so no 2400 or Unique.

Are your cases trimmed to the proper length?

quote:

Alliant powders are hard to come by in Australia, so no 2400 or Unique

Same here in the States. Unique is scarcer than hen's teeth!

? Is a double charge possible!!!!
You don't mention the actual charge used.
But a double charge, if possible, would certainly cause hard bolt lift. Maybe much worse.


muck

Yes the case are the correct length.

A double charge is possible, but would bring fill to around 90% 0of case and so would be obvious.

Sound unlikely, but could too much alox on the bullet migrate to the mouth/neck area of the case and start sticking cases to the chamber if it built up? The rifle was not cleaned in between trips to the range!

quote:

Are there any other causes than high pressure that would cause a lever action rifle to be very hard to open?

Why start looking for exotic explanations when the most obvious will do?

quote:

Background, I have put a fair number around 100 rounds through this rifle using trailboss and H4227 with no problems what so ever.

Hmm,,,, Rifle works fine otherwise, this might be an important clue.

quote:

I obtaine a load from a third party, published, but not by a major reloading, powder or bullet manufacturer.

The obvious answer is, this load is not appropriate for the application. I talked to Alliant about loads disappearing from their factory manual and guess what, with the piezoelectric real time pressure gages et al, they can see things now that they could not with the old copper crusher system. They can also see such things as powder, primer, case combinations that are not appropriate. Appropriate in that the load combinations are too sensitive to component changes, powder increases, etc. An example is the reduced loads of Blue Dot in rifle cases that I occasionally hear about. I ran into a guy at the range, he loved his Blue Dot loads in the 223, shot accurately, did not heat up the gun, small powder charge, cleaned up great. However, Alliant does not recommend Blue Dot in the 223 because small variations in things will spike pressures, and there are reports of rifles blown up with Blue Dot, even though the owners were certain all charges were weighed.

I think your not recommended factory load falls into this category. Who knows what the exact problem is, other than the powder/bullet/case combination is not appropriate and you are getting pressure indications, even though your Computer Thingy says everything is OK. The Computer Thingy is just someone’s model of reality, it is not necessarily reality.

At some point in time, you have to ignore the GPS navigational device and use your own judgment.

As my Mom said “if everyone jumped off the cliff, would you?”

Man drowns after GPS guides him into Lake
http://gizmodo.com/5655527/man...ides-him-into-a-lake

Girls drive into Lake following GPS directions
https://www.youtube.com/watch?v=a2QIH2uz3p8
Truck Drives Into River, Driver Blames GPS
http://wnep.com/2014/05/23/tru...e-driver-blames-gps/
More humerous GPS accidents.
http://www.oddee.com/item_98264.aspx

I am going to word this in the strongest language I can, it will leave no doubts.

There are two main causes for heavier than normal bolt lift:
1. Rough chamber finish

2. excessive pressure.

Since you have not experienced the heavy bolt lift with other ammo I will tell you that you are operating beyond the pressure limits of your gun. Since it is a lever action and not a bolt, it is likely enough to damage the gun and injure yourself over time.

I don't want either to happen. Please forget this load and use tested and proven reliable data.

Well I have always fancied a 44mag. This 2lbs of powder is a good reason to get one!