7x57mm Load

[tbierley]

I have tried Trailboss with 139 and 174 grn fmj bullets and shot very well. But today was going to try 23grn of H4895 this is going into a 1902 Remington Rolling block. Can I get some load data for this round the power I have on hand is Varget and H4895. My loading book does not low pressure load bata. Thanks

[Nobade]

What bullet, what seating depth, what pressure do you desire?

[tbierley]

Bullet 140gr seating depth of 2.800 an pressure of 30k and the powder of Varget or H4895. Thanks

[Nobade]

Just randomly picking a 140gr. Speer bullet and given the rest, I get 34.0gr. Varget and 33gr. H4895. Both should generate about 2350 fps at 30,000 psi. The 4895 should burn slightly more completely and possibly be more accurate, but you'll find that by shooting.

Keep in mind this is from Quickload which can't take into account things like throating. Be careful out there but this should get you into the ballpark.

That is also quite a bit shorter than the max allowable OAL length on a 7X57. You likely will find you can seat the bullet out quite a bit from 2.8 inches. That will lower the pressure a bit, so keep that in mind too.

[EDG]

Check your chamber and headspace in that RRB 7mm.
Those are known for being non-standard for some reason.
In addition make sure the firing pin looks like a modern FP for diameter and projection.
A pierced primer at the high pressure of the 7mm in a RRB will blow the hammer back.
Once the hammer rolls back It will open by itself right in front of your face.

[Buckshot]

Check your chamber and headspace in that RRB 7mm.
Those are known for being non-standard for some reason.

Close the breechblock, ease the hammer down under it and then pull back on the breechblock thumbpiece as hard as you can for a few seconds, then while continueing with the pressure, look between the breechface and the face of the breechblock. THAT will be the headpsace issue with which you should be concerned. That will be the unsupported portion. Headspace in the Rem RB is made up of the 'Stacked' clearances of the pins in the frame, the pins and the hammer and breechblock, and finally that clearance between the hammer and breechblock themselves. The case will fireform to the chamber's internal dimensions. After that you'll want to only necksize. When the rounds exhibit a bit of 'snugness' when chambering, you'll then need to Fl size

In addition make sure the firing pin looks like a modern FP for diameter and projection. A pierced primer at the high pressure of the 7mm in a RRB will blow the hammer back. Once the hammer rolls back It will open by itself right in front of your face.

I'm having a bit of trouble understanding how the hammer will roll back with a pierced primer? Does this happen via the firing pin pushing it back or high pressure gas flowing past the firing pin do the work? A smaller OD firing pin following more modern practice is desireable, however more important then OD is length. A small OD firing pin will penetrate a primer easier then a pin with a larger OD, assuming both have the same length.

My 1897 Rem RB 7x57 has a firing pin of larger OD then would probably be considered 'modern' but it doesn't dimple the primer to any troublesome depth, and has performed quite well, lo these past 12 - 15 years. I haven't loaded and fired any modern 7x57 ammo in it but I have fired reloaded Rem 175gr jacketed at 2400 fps, which is the historic ballistics of the cartridge, and with the right powder (I used surplus WC872) will produce it with less then 40,000 psi if that's what you're looking for. My 2 favorite cast loads using either the RCBS 7mm-168 or the 150gr Lyman 287405 Loverin was either 23.0 H4198 + dacron or 42.0grs Surplus WC872 + dacron. Both gave 1750/1775 fps with the RCBS and about 30 f[s faster with the lighter Lyman slug.

................Buckshot

[tbierley]

Could you post a pic and a size of the firing pin. The firing pin in my looks small and hits the primer very hard.

[atr]

EDG is right on about the firing pin !! Believe my I have BEEN THERE !
and ye my RRB does have a very liberal (ouch the word) chamber. Buckshot is right also about fire forming and then only neck sizing. For some reason I have found that resized GI Brass seems to work best in my RRB 7x57
From a rest and using a 135 gr boolit at 100 yds and the stock military sights I can usually hit a "clay"
my go to powder is IMR 4895
if your boolit drops fat (mine does) then you might NOT want to size them but use pan lubing and keep the diameter large.

[EDG]

>>>high pressure gas flowing past the firing pin do the work?<<<
This is what does it. I think some of these rifles must have been modified for the chambers to be so much longer than the loaded round. In any case be careful. The rifles are strong but they have to remain locked. If they do have a leak or open it is pretty close to your face.

[tbierley]

I loaded up some with 30grns of H4895 and with a 140 FMJ bullet. I have about 1000 mil spec 30/06 case.I am going to cut them down and resize and fire form them and then load them with H4895 and 33grns and then try it. Going to get a mould and start casting like I do for very thing else I have. I have a Lee 185 mould I was thinking about resizing to .185 and trying that.

[Buckshot]

Could you post a pic and a size of the firing pin. The firing pin in my looks small and hits the primer very hard.

.............I'll try to remember to get a picture taken of it.

I think some of these rifles must have been modified for the chambers to be so much longer than the loaded round.

............I've heard it enough about chambers to believe that something must be up with it. The only problem I have is that a fireing a round results in a caseneck ID almost large enough to pass a 30 cal slug. Other then that, no problem. Now, if you're one who likes to FL size their cases for every reload, I doubt the brass will last as long as you'd like before you begin to get partial casehead seperations. Simply the nature of the beast. Due to the design and the required tolerances at manufacture (plus the additional aquired over years of use) as I mentioned in my previous post, it's gonna happen. So only neck size, and then FL size only when you have to, and your brass in that rifle will give you good service.

I also anneal the casenecks after every 5 firings. On the side of each box of brass I have, and each rifle has it's own dedicated brass, I have a 1" x 3" lined adhesive lable. Top line lists the caliber, ie: 7x57 and it's "Trim To" length. Below that is "Firings", and each time it's fired I draw a line. Below that is "Annealing". If I annealed after the 5th firing, a line is drawn under the 5th firing mark. Finally on the bottom is "Trim" and it's the same as annealing. Say I have to trim the cases on their 8th firing? On the Trim line directly below the mark for the 8th firing I place a mark.

For example, some 30-'06 LC45 brass I use in my 1903A1 Springfield has had 32 firings. On the "Anneal" line you might see where it was annealed at the 6th, 14th, 21st, and 28th firing, and on the "Trim" line it was trimmed on the 8th, and 17th, & 26th firing. Works for me and lets me know when I need to start checking case lengths.

................Buckshot

[tbierley]

On the rounds I loaded I neck sized the 7x57 brass I had on hand. A FL sized the 8mm brass I had on hand. And you are right the neck is opened up all most to the point I can put a .309 bullet into it. I was thinking of trying a 30/06 case that was to long and trim to the point that case will sild into the camber and the breech will close and lock and then fire form it with a light load.

[Ed in North Texas]

The issue of larger than SAAMI standard chambers on the Remington 1897/1902/1910 7x57mm (AKA 7mm Spanish marked on some) has been known for a long time. I can remember reading about it in (IIRC) the American Rifleman in the 60s. The answer then, as now, is to neck size instead of full length sizing your fired cases. Once you have a fire formed case, why re-size it to SAAMI specs for a non-standard chamber?

As for catastrophic failures of the RBs, I recollect seeing pictures of one such event. I do not remember whether it was a No. 1 or No. 5 action. If a No. 5, I don't recollect whether it was in the original caliber (and there were several other than 7x57mm). I do believe it was not an issue of a standard pressure load with no mechanical problem (e.g. barrel obstruction) which caused the failure. Such problems can occur with any firearm, and are "reported" far more often than actual occurrences. Given the number of RBs out there, the probability of a failure is quite small. Of course that doesn't mean one should pursue the old American penchant for squeezing the last possible foot per second velocity out of a RB. I have 3 Rollers, one is still shooting after 140 years, another after 137 years and the last 101 years. I treasure these as classic examples of an American gunmaker's product which I intend to shoot and keep in good condition for my Grandsons and (hopefully) their Grandsons.

[Nobade]

I have been wondering why some reloading die maker (maybe CH4D) doesn't make a set of dies specifically for this rifle. Are the chambers all different, or are they standardized enough for that to work? I have wondered the same thing about the Lee Enfields and their 303. There were so many of both types of rifles made and most folks know normal dies don't work with them.

[MtGun44]

A friend got a 7mm RB 1902 back in the mid 60s, and he tied it down to a tire for the
first shot. It seemed to go well but when he looked at the gun, the hammer was back,
breech open, chamber empty. WHAT????????

One more time, watching the breech and hammer very closely now. ZIP -----> the
case went flying backwards at high velocity; ended up hammer back, block open,
chamber empty. WOW!.

Finally found the case. Pierced primer. We figured it popped the firing pin back hard
enough to cock the hammer and this unlocked the breech block with enough residual
pressure to SMARTLY eject the case. Good thing he didn't shoulder fire it the first time.

Shortened and rounded the firing pin and all was well.

Try 35 or 36 gr of 4064 under a 175 RN Hornady. Shoots extremely accurately and to the sights
on my 1902.

Bill

[Ed in North Texas]

snip

Shortened and rounded the firing pin and all was well.

snip

Bill

Because this is not an incident common to all No. 5 RBs, I wonder if the firing pin was a replacement. I could be mistaken, but I would think it difficult for that rifle to leave the factory in that condition and survive unchanged from shipment to the time your friend bought it. I guess it is possible that extensive firing caused firing pin peening of the inside of the breech block, and that might eventually have allowed it to extend farther out of the block (depends on the relative hardness of the block and the firing pin). Was there any evidence of that having happened?

While I hate to alter original firearms, I will probably shorten the firing pin (better yet, get a new, shorter, firing pin and save the original) on my NYSM as the original is much too long for modern CF cartridges. But in testing loads (BP) I've used Magnum, LR and LP primers. None were pierced.

Also important in this is the idea of safe firing of the first round in a "new to me" older firearm. When I took a couple of older rollers to the range the first time, I also took a Redhead Magnum Rifle Rest. One of the other club members saw the rest and was about to lecture me about using the rest, sighting in and accuracy when I told him I only used it for safer firing of the first few rounds out of a new rifle.

[MtGun44]

He assumed that someone had replaced a broken firing pin and not test fired the
gun. I am VERY loathe to fire a new milsurp in the normal position. I almost always
set it up in a rest and trip it from max arm's length, then examine the fired case closely
for anomolies.

Bill

[atr]

BILL !!
Pardon me but I had to laugh, when I first got my old RRB I also tied it to a tree in the backyard and "tested" it with some old surplus ammunition.

[MtGun44]

A dismounted car tire works as a great test fixture. Stick the buttstock into one side and
rest the forend straight across on top, tie a loop on a string through the trigger guard and
retire as far as you think is needed. The rubber won't hurt anything.

Bill

[Yance]

On the rounds I loaded I neck sized the 7x57 brass I had on hand. A FL sized the 8mm brass I had on hand. And you are right the neck is opened up all most to the point I can put a .309 bullet into it. I was thinking of trying a 30/06 case that was to long and trim to the point that case will sild into the camber and the breech will close and lock and then fire form it with a light load.

For my "new to me" 1902 7MM, notorious for having more than "generous" headspace, I formed and trimmed Federal '06 cases moving the shoulder back just far enough to allow the hammer to fall. Loading with 34.3 gr IMR 4895 and a 140 gr Nosler I test fired it into the ground, one handed, face turned the other way. I had much less case body expansion than expected but the ID of the neck had expanded to .294.

Firing pin in this one is the small diameter "smokeless" version.

[mroliver77]

I have never read in a loading manual or manufactures directions for the use of loading dies about "custom" sizing a case. I think that the concept should at least be metioned especially where older or military cartridges are concerned.

My first reloading venture was forr a Jap Arisaka that my Dad drug home from WW2. It had an oversized chamber but I happily leaned on the handle of my RCBS press and smooshed the cases way back down in size only to be stretched way back open again. The directions with the dies said to be sure that the shell holder touched the die bottom. The Sierra manual told me to follow manu8facturers directions exactly. No mention was made in the manual about the well known issue of Jap chambers and Norma brass being out of spec. Sigh!

My second venture was a Spanish Mauser rechambered in .308. It was oversized and stretched brass. If I had known how to properly set up the full length dies it would not have been an issue.

Thank God for the internet! I have a 1902 RB remade into a 45-70. When I first got it I measured and read and ciphered to figure the max pressure I could load the ammo to. After finding pics and articles of what happens when a RB has problems I rethought the issue. I now consider only very conservative loads for the RB. The design does not handle escaping gas well at all!
J