Hi all -

This is a cross-post from another forum, for folks who may not see it there.

My question is:
Have you ever blown up a Marlin .45-70, or PERSONALLY know anyone who has?
If so, what load/conditions brought it about?

PLEASE PLEASE PLEASE -
NO war stories about shoulder-breaking loads that DID NOT result in a blow-up. I shoot heavy loads myself.
NO sad tales of of other rifles blown up. I've blown others myself.
NO interesting experiences that have NOTHING to do with the question. I'll read & enjoy them on the forum.

AND ESPECIALLY - PLEASE DON"T RECOMMEND THAT I NOT BLOW ONE UP!!

I'm not going to - I just want to know what DID, if anything ever HAS.
But if I do in the future, I'll let you all know the REAL MAX PRESSURE a Marlin can take.

regards,

Nope, but while your waiting for a reply take a look at this thoughtful little article.

http://www.real-guns.com/Commentary/comar52.htm

Hi William -

Thanks for the link - very interesting.
Looks like QuickLoad'd be a very handy thing for a reloader to have.

I've seen 2 articles (don't remember where) about Marlins blown up by "60,000 psi or more", but that was just guesstimated.

In light of the tremendous amount of discussion of this topic found on any forum for Marlins, I'm curious to find if any of the opinions have factual basis or if it's all just what makes somebody happy.

"Conclusions are what you reach when you get tired of thinking." :-)

regards,

"NO sad tales of of other rifles blown up. I've blown others myself. "

No offense, and from the sound of it maybe there have been more than one, but wasn't that enough?

There is a lab that is used by many to proof firearm, I believe their name is White Labs, or something like that. Maybe someone else can elaborate. Give them a call. Perhaps they will tell you. At any rate I'd rather pay them to do it than find out myself. Just a thought.

Hi Bart -

My apologies - I'd hoped my feeble attempts at humor would be pretty transparent.

Sad fact is, I've done lotsa dumb things in 40+ years of gunnuttin'.
But ONLY 1 (!!!) blow up & bro, you're SO right - 1 is PLENTY.
On the upside, it WAS cheap and VERY instructive (as well as destructive).
Actually, it cost me less than a lot of the trades I lusted WAY too much for over the years! :-)

I'm trying to get any first-hand reports there may be about this matter because it seems to be perhaps THE most discussed topic on any forum about Marlins - well, mebbe 2nd to "NipWin 1886 or 1895CB". :-)
There seems to be little more than opinion, thrown about with great abandon, legitimized at times with reference to this or that guru. And as far as I know, the gurus don't publish their data either. I'm no sheep to simply accept whatever "authority" expounds.
I can think for myself, and I CAN DETERMINE properly and appropriately for myself when given correct information - I suspect you and most who may read this would characterize yourselves likewise in matters that are of interest to you.
I deeply respect MANY folks for their knowledge and experience, but I've heard/read lotsa my heros say dumb things 'cause they didn't THINK of the implications or examine their (ofttimes unrecognized) assumptions.

Also (this is one o' them "personal" deals) I already have the 1895CB....
and H.P. White wants cash!!!!

God's best to all!!!
regards,

Nope, but while your waiting for a reply take a look at this thoughtful little article.

http://www.real-guns.com/Commentary/comar52.htm
Maybe I am not reading his article correctly but bolt thrust should be expressed in units of lbf (pounds-force). Multiplying lbf/in2 by in2 leaves lbf.

The description of the bolt lock up was not clear. He seems to be implying the lever is what locks the bolt in place when actually it is the rear locking logs. See the image below.

Otherwise a very interesting article.

Below is a link to the H. P. White loboratory page

http://www.hpwhite.com/

I think Joe has a good article. It is hard to write clearly on this subject. I think he meant to say that the lever assists in the lock up.
I have had the .307 Winchester kick the lever on hot days with high pressure loads in my Winchester Big Bore. I am talking about above 90 degrees. This will get your attention. Joe has probably had this happen to him. Things are sort of inbalance With alever guns lock up.

I have seen back thrust expressed several different ways. None of them seem really clear to me!

Seems the figures in the radial/hoop strength section are worth a a good look.

Haven seen a couple of actions taken apart (but not by me...and no one knows what the owner actually crammed into the chamber to take it apart) and the published pictures. Seems the major failure is at the barrel shank, splitting the barrel and action at the reciever threads.

How much pressure it takes to do that isn't real clear. But while the bolt is set back and damaged, the point of failure isn't the bolt or the rear of the reciever.

Know it's not the main thrust of this discussion. But in all the blown up rifles (and shotguns) seen first hand or in published works, the filure is very seldom at the rear of the system...either the case lets go and the gas goes on a rampage or the thinnest section (usually the barrel shank) lets go in a radial pattern, taking the threaded front of the reciever with it.

How much bolt thrust is related to how much of a safety factory you are willing to live with. Old data from Ackley (still valid) shows a non-tapered case in a clean chamber not offering much in the way of bolt thrust...but you have to wonder what happens in real life after four or five shots when the chamber is a little fouled or when the cases are a little greasy or the ammo is wet.

"Best case" measurements vs. "worst case" seem to be pretty wide...which is the reason for the margins of safety.

the published pictures. Seems the major failure is at the barrel shank, splitting the barrel and action at the reciever threads. .

You hit the nail square. I have seen some of those pictures also. The failure is right where the barrel steel is the thinest.
There was a recent classic picture of a Marlin 336 that opened up floating around. I dont know why i didnt save it. A Winchester could fail in the same spot.

Rigby275 - You might want to check out this link
http://leverguns.sixgunner.com/topic.asp?TOPIC ID=2060

Hope this helps Ron

Hi Ron -

That link takes me to Leverguns general forum - fine folks, but I dunno how to find a specific thread w/o going thru ALL of it since it's an "information stew" there - everything thrown into one pot!
Thanks for trying.

regards,

This is a good one,buckle your seat belt and hang on as these boy's tell it like it is.Very interesting though.Jayco.
http://leverguns.sixgunner.com/topic.asp?TOPIC_ID=2060

Hi all -

That's some VERY interesting reading jayco (& Ron) -

Seems like Buck Elliott knows how to blow 'em up RIGHT! :-)

Reading all the test/personal experience/fact. load data around, I'm now real comfortable with 44K as a SAFE tho' mebbe wearing (gun & shooter) top-end for .45-70 Marlins, with 40K a reasonable & satisfactory top.

Bring in the Garrett test info jayco gave on the "HEAVY LOAD" thread, and I'm tickled to death (soon to be beat to death) by what these beaut's will handle.

A little OT, but the talk @ Levergunner about other rifles, specifically the '95 Win, combined with the penetration results Garrett got w/300Nosler/.45-70, gets me to wondering what the story is on the .405 Win. (300/2200) - everything I've read about that cartridge claims it's failure as an African round is due ONLY to it's low SD - no penetration!
Seems to me 2+2 ain't equalling 4 there! :-)
Could be the Noslers were the magic ingredient and that inadequate bullet construction, not inadequate SD, brought down the .405.

Y'all (I'm an African-Scots-Confederate-American) having cooled my fevered brain on the pressure question, I'm gonna wander over to the "HEAVY BULLET" thread & see if I can stuff about an ounce of Pb (powder & projectile) into a .45-70 and launch it @ Mach2. :-)

Thanks all!

regards,

The radial/hoop strength may be the issue with the Marlin in 45/70 cal. I've seen one Marlin 45/70 barrel that was cracked on the underside where the barrel is milled out for magazine tube clearance(a consequence of putting the 45/70 round in an action designed around the 30/30 cartridge) The gun was rebarreled and is still being used. the gunsmith that showed me the barrel said he had either seen a couple more or had heard of a couple more Marlin 45/70's that had the same thing happen. I don't know what the load was, but it would be a good idea to keep an eye on the chamber, and be very attentive to case bulges and/or sticky extraction.