Hello everyone and I hope the experts don't think that this is another silly question from India - in studying various bolt action designs, my very amateur understanding is that action strength depends on sheer size, contact area of the lugs and venting. However, a lot of companies and writers make unusual claims about bolt action strength. For example, an article in Gun Digest 1984 says that the Arisaka rifle action was the strongest of all ever made, the Weatherby company claims that their action is the strongest and that it could withstand cartridges with 100000 CUP while articles in Sporting Rifles magazine by Chris Bekker doubt that this action was ever tested at such high pressures since the author claims that such high pressures would completely destroy the brass cartridge case. I don't know whom to believe.

Additionally, if I know right, the Arisaka was a Mauser rip off and if it is indeed the strongest bolt action ever designed, and if indeed it is CRF, why aren't Arisaka type actions being made for high quality custom rifles?

Please excuse these questions if you think they are somewhat silly. I am just an interested man looking for some answers to doubts I have.

Mehul,

The Arisaka may have been the strongest military rifle ever made, but being the strongest in a class of action that is over-designed for strength anyway is of little true benefit. That and the short throw (and being butt ugly) make the Arisaka forever a milsurp rifle.

Any of the modern bolt actions is much stronger than it really needs to be (and probably stronger than the Arisaka). They are typically designed to function properly after a 60% over-pressure, and most will not catastrophically fail in a single 100% overload event - as long as the cartridge case does not rupture.

Since the actions are all so much stronger than the brass, the big difference is what happens when the cartridge case fails. When the gasses get loose they tend to pressurize voids that were not designed to hold pressure, and gunstocks, magazines, etc, become secondary projectiles that do most of the damage. Again most bolt guns have friendly failure modes for gas venting - for right handers. (If you are a lefty, by all means get a left-handed action.)

Thus the choice of modern action devolves into a personal choice. Push-feed vs CRF, two lug vs three, etc.

Don

mehulkamdar,

The author may have meant that Arisaka is the strongest "military action"
ever made. Like DonG said, the rifle is not a good looking one, unless you
want a rifle that comes with a dustcover. Mosin-Nagant is another action
with exceeding strength, but it's design is not favorable.

I don't know how to contain 100000PSI of pressure in a brass case, but,
it doesn't have to be a brass case(It might as well be a paper roll filled with
TNT). I know early Mauser 98's are proved at 100000PSI as well.

There is a great deal of information in P.O. Ackleys books on the this subject - good reading.

A 6.5mm Arisaka rifle made prior to the dire days of the end of WWII appeared to be the strongest bolt-action military type rifle tested by P.O. Ackley in hios famous "blowup tests" of military bolt actions following WWII. They exhibited the "most elaborate heat-treating ever seen", with different hardnesses at various appropriate locations, even on the striker! (Anyone who could temper a Samurai sword should have had no trouble with something as simple as a rifle action!!) I have seen several pretty nice sporters made on Arisaka actions. However, some of their OTHER design features, such as their hard-to manipulate safety, crude bolt handle, ugly trigger-guard/floorplate assembly and strange tang setup made it difficult to do anything with them as far as style, elegance, and ergonomics are concerned. But there was basically nothing wrong with the 6.5X50mm round for deer and black bear, and when recahmbered to the 6.5X57mm cartridge, they were in the same overall class as the .260 Remington. I have also seen a couple of sporterized Moisin-Nagants that came out pretty nice despite their strange box magazine. But with these, you're pretty much stuck with the 7.62X54R Russian cartridge.

Looks like P.O Ackley wrote some interesting stuff, what are the books to
read?

Pyrotek-

Handbook For Shooters and Reloaders, Vols. I & II.

The strength of military actions is "discussed"
in the first chapter of Volume II.

Both books are excellent reading for the rifle nut. (Some of Mr. Ackley's load data is considered to be on the hot side. Use caution...)

Bob

If the brass cases are the weak point, would a steel case allow higher pressures? If the case withstood 90,000 p.s.i. loads, what is the next weakest link? The primer?

H. C.

Thank you very much everyone who posted annd especially J Belk for forwarding a number of excellent attachments to my e-mail account.

I shall study the info that he has sent me in context with some material that I have - I have learned a lot from everyone here, thank you.

As a rough aside, I lived in Russia for some years and most hunters there used old Mosins converted to a 9mm cartridge as well as stock Mosins and everyone who used one loves them there. My only gripe was that they were very long, though they balance well. Recoil, too was non existant thanks to the length and weight.

Mehul, there is one other issue about the Jap rifles that makes them very difficult to convert into sleek sporting rifles. The SAFETY.

The large rear knob on the bolt, as you know, is the safety. To engage or DISengage the safety, one must push this knob inwards a considerable distance and rotate it almost 90 degrees. This is an awkward maneuver under normal circumstances and dang near impossible with a big scope mounted above the bolt.

And I'm not sure if anyone ever created any after market product to correct this issue.

I have seen a couple of Jap rifles made into good looking sporters, but they still had this safety problem.

I understand also the Japs weren't terribly consistant with their bore diameters either.

Bottom line is I wouldn't throw away a Jap action if I had a good one. They are, with these exceptions, good actions. And for sure strong.

Regards - Pecos

HenryC470---

The primer is the weak link now.

Unless there is an advance in electrically fired primers they will always be the weak point because they have to be soft enough to dent with the firing pin spring but also have access to the firing chamber.

Steel cases don't seal to well and can cause problems at high pressures. Steel is also very suseptible to gas cutting....and if it does.....it causes major damage to the poor guy holding it.

There are two theories of action strenght:

1) The Mauser method-- Design the action to allow any failure to expend it's energy away from the shooter. Look at any fireworks factory or explosives company and you'll see the same thing. Divert, slow, and direct in a safe direction any explosive force and debris.

2) The Remington method--- This method *seals* the action against leakage. The bolt head is enclosed and fits into a barrel recess.
These actions take more pressure without damage....BUT, when they fail they fail in a big way. Injury almost always will occur if the case fails.
The mechanical operation of this system precludes controlled round feed and large, dependable extractors.

Everything is a trade-off. Take your pick.

JBelk, I think I'll try to pick safe reloading practices. I've seen enough wrecked guns to know I don't want any part of holding it when they come from together.

[ 07-02-2002, 00:21: Message edited by: Pecos45 ]

I agree the pedigree of the Arisaka strength legend traces to Ackley.

This last week I have been trying to research the "springyness" legend of British Enfeild actions.

Again, I can find no sourse other that Ackley, and then the Speer and Hornady load books copyied.

Pesonally, I have worked up a 1903 Turkish Mauser, VZ24 Mauser, and a Russian 91/30 to the point of having to pound open the bolt with a mallet. I have done worse with a 1938 Turkish Mauser, in that the primer pocket opened up to a much larger diameter as well as needing to be pounded open. None of these bolt actions failed or lost head space.

Contrast this with what happened when I worked up at .1 gr of powder at a time to see what would happen in semi auto pistols and revolvers. The semi autos blow out thier cases down the feed ramp and into the magazine. The revolvers split their cylinders.

My sample of 4 bolt actions shows them to be stronger than the brass. I hope to soon test a few Enields.

I have a couple of Finnish Mosin Nagants, and I'm intrigued by comments on the strength of the action. How do these compare with actions like the Mauser? In the event of a pierced primer, or case head separation, how do they vent gas?

My 91/30 that I tested with 180 gr Sierra, 50 gr IMR4895, jammed into the lands, made the bolt jam [just like a Mauser 98 action]. 49 gr is ok for bolt sticking, the accuracy was at 46 gr.

I know a guy that has been experimenting for 35 years on Russians, and he drills and taps out the bolt face and adds a part. Then he turns down the firing pin. He want a smaller firing pin hole for Boxer primers.

Here are my notes:
7.62x54R
"Modern Relaoding: Richard Lee, 180 gr 38.7 gr, 2.952" 2454 fps
I like the Sierra .311" dia 180 gr SPT bullets the best in my 91/30.

I have also used the Remington 180 gr bullets.

I can neck size the 7.62x54R cases by not resizing all the way. This is
in part possible because of the case design's steep taper.

Reloaded with neck sized cases, CCI 200, 2.843" OAL, and IMR4895 powder
shooting 3 shot groups:
40 gr 2.7" 41 gr 2" 42 gr 2.25" 43 gr >4" 44 gr 1.2" 45 gr 2.9" 46 gr
1.4" 47 gr >4" 48 gr 2.5" 49 gr 3.3" 50 gr 2.5" w/ sticky bolt

I reloaded again:
43.0 gr > 2" 43.3 gr 2.4" 43.6 gr 3.5" 44.0 gr 2.1" 44.3 gr 1.2" 44.6
gr 2.2" 45.0 gr 1.7" 45.3 gr 1.7" 45.6 gr 4.5" 46.0 gr 2" 46.3 gr 2.6"
46.6 gr 4.6" 47.0 gr 3.2" 47.3 gr 1.3" 47.6 gr 3.8" 48.0 gr 2.2" 48.3 gr
2.7" 48.6 gr 3"

I like Lapua brass much better than S&B. The S&B Boxer brass has two
problems:
1) the base of the primer pocket has too large a radius and needs
reaming.
2) The handloads are not as accurate as the original ammo.

The factory loaded ammo:
7.62x54R S&B soft point 180 gr. ammo 2" 3 shot groups at 100 yards

I have been getting the rifle on the paper with surplus ammo from
Century.

LE270,

I think Jack is talking about much bigger pressures than what you are referring to.

Back in the late 60s when I first really got involved with experimenting, we used the M17 action and took off the extractor and of course the stock.

It would take a big load to blow an M17 apart.

Mike

LE270---

What you're seeing is the gas that leaks through the firing pin hole when the primer blows. That's "warning pressure", not dangerous pressure.

The next step up in pressure cuts through the thin web of the bolt face around the extractor. That melted steel and brass and gas will come down the left locking lug raceway and hit the shroud. At least one eye is nearly always lost. Left-handers shooting right-handed rifles usually lose both eyes.

How can you call me wrong when you haven't seen it or tried it?

Lee Enfields are indeed springy. It is not necessary to take my word for it but I've been reloading for them for nearly 40 years. When loaded to destruction the Lee enfield receiver will bend down ward and the bolt can bend in an "S" curve. I know this because I've done it!(deliberately). Even at this the shooter would probably not have been injured other than developing a severe flinch!
When it comes to the effects of severe overloads in Remingtons and others I have seen it. Lots. I've not seen a case where there was any injury to the shooter and some of these cases were severe indeed. The type of failure Jack mentioned must have happened somewhere or he would not have mentioned it but in order for it to happen at all there would have to be some problems with the fit of the barrel to the bolt (not impossible given Remingtons quality control standards at times).
I have seen 700s where the pressure was high enough to stretch the receiver ring but there was no failure of the gas seal. The nose of the bolt expands until it contacts the barrel counterbore and stops there.
In one memorable case a customer had me barrel two Remington 700s for him. Both Classics. One was a 7 STW and the other was a 308 Norma Mag. He loaned the 308 Norma to a client and guess what? One day the client grabbed the wrong rifle and got the 7 STW by mistake. He had the same ammo though and when he got a chance at a decent grizzly he let him have it with a 180 Swift bullet from the 308 norma case fired in the STW. Apparently it kicked pretty hard, the bear was well hit and dropped like a stone. It was well that he did since there would be no follow up shot. Back at camp the outfitter casually knocked the bolt handle off and so brought the rifle to me. I pulled the barrel and removed the fired case which was practically brazed to the bolt. The bolt face showed some minor gas cutting but nothing that was too bad. The extractor was ruined as was the ejector and spring. The striker spring was partially collapsed. I replaced the extractor, ejector and springs and reinstalled the handle. Headspace appeared to have grown by about.002 but was still within tolerances. Barrel and chamber was fine and the rifle is still in use today (this was 10 years ago). In this case the barrel counter bore was more closely fitted than Remington does it so may have had some bearing on the result.
As Jack mentioned the Mauser dumps the gas in a (hopefully) safe direction. At least it is safe for the shooter. I sometimes wonder where the missing extractors went and what would have happened to someone standing to the right.
The pre-64 M70 is one that is designed to direct the gas into the shooters face via the left locking lug raceway.
Ruger 77s dump the gas into the mag well and as long as you don't have your hand under the floorplate you will probably be ok.
The primer is the weak point because many actions have firing pins which are too large in diameter as is the hole in the bolt face. New Model 70s that are blanking primers are cured by bushing the boltface and reducing the pin diameter. Then the brass case is once again the weak link. This is necessary mostly for those who are loading hot with cartridges using the small rifle primers. The long range shooters using 6BRs are the most common offenders. Regards, Bill

LE270---

Not a problem.

I think what got you confused was thinking when I said, "These actions take more pressure without damage....BUT, when they fail they fail in a big way. Injury almost always will occur if the case fails."

I was referring to the action failing and not only the cartridge case. Sorry for the misunderstanding.

The 700 series Remingtons will take a tremendous amount of pressure before it fails to the point of injury. I've seen (and now own) two Remington actions that could only be taken apart by pulling the barrel, unsoldering the bolt handle, and driving the bolt out the front. (No injury except to shooting glasses and underwear.)

It *can* be argued that a false sense of securiety is developed when blown primers don't send a strong enough message to the brain-dead shooter when shooting something like a Remington "sealed" action.

With a M-98 type the floorplate blows out and many times the stock is broken. That's a pretty good signal that pressure has exceeded good sense.

A primer leak and a case head separation are not case FAILURES, in the sense that a case failure releases all the pressure back into the action. In case head separations, there is ususally enough of the case wall ahead of the web left intact to seal the breech, even though the front part of the case remains in the chamber. Case head separations are not the result of excessive pressure, but occur because a case was stretched on initial fireing, then reloaded enough subsequent times that the stretching continues until the head separates. This has happened to me in .348 cal. M71 Winchester rifles with no dire results at all. A case-head rupture caused by extreme pressures, however, is another animal entirely, and when this occurs in a "safety-breeched" action, like the Remington 721-700 series, the velocity of the escaping gases is accelerated by the small apertures through which they have to squirt to get out. When this occurs, the results are usually more dire than in the case of a Mauser-type breeching setup. I believe this is what J. Belk is referring to.

John,
I have exceeded a maximum in the Ackley books, and it is posted above.

The 8x57 and 7.62x54R max loads in Ackley are about 2 gr below sticky bolt.

As Red Green says, the three words men can't say, "I don't know."

LE270---

A little off-topic, but important.

You say the Fed 210 were "blowing" and others didn't.

Just to be clear---did the primers blow around the edges or did the primer "pierce" where the firing pin hit it?

Federal had a reputation for soft cups and sesitive mixtures during the 80s.

You can replace the firing pin spring with a Wolfe's spring 2 pounds stronger and cure the piercing problem, if you like.