Scattered groupings, don't know why

[Suzanne]

I've been loading 8mm Mauser and had really good luck with Win 748 and 150gr Hornady sp bullets. I wanted to start using some 180gr Nosler ballistic tips for hunting and found some load data for Win 748 using from 42 to 47gr. I chose to start at 44gr and see what happens, well the bullets are all over the place. I'm using a bench rest at 100yds and getting wonderful small groups with 150gr Hornady spitzers but not with the Noslers. The Noslers are boat tails the Hornadys are not. Well the other variable is that the Nosler bullets have to be seated deeper than the Hornady. I did a measurement to find out where the rifling starts and found my ideal length would be 3.155 inches. Interestingly I found that one wouldn't chamber and so I reduced to length to 3.135 inches. I have had one suggestion that, "maybe the powder isn't filling the case enough and that the powder (being a medium burning powder) needs a magnum primer. I should try a max load and see what develops." One thing I don't want to do is try and find some $75 worth of primers that may not do me any good. I can try heavier loads and I also have some H-4895 (but not much). Any suggestions?

 

[rcmodel]

I think that WW-748 might a scooch too fast for heavy bullets in the 8mm Mauser.

It is also ball powder, and Mag primers are generally suggested for ball powder.

It could be that your medium level load is not bumping up the Nosler bullet and sealing the bore well, or it could be velicity is too low to stabilize the bullet in your barrel.

H-4895 is a little faster then WW-748, but it is not ball powder, so should ignite easier with standard primers.

SO:
You could try upping the load of WW-748 a couple of grains.
Try Mag primers with the WW-748.
Try the H-4895 with the Std primers you have.

rc

 

[GodGuns&Guitars]

Loads

Are you sure it's because of the loads? Could be the scope has loosened up or even the mount screw/screws that weld the stock to the rifle have loosened up. My groups with my 300 weatherby did that once and I found the screw that mounts the rifle to the stock was loose. Just some things to consider.

 

[Suzanne]

Well I just ordered a bullet puller collet and I'm going to pull the rest of what I've loaded and try the H-4895, I have load data that starts from 41gr to 47.7 grains, maybe I'll stick with my lucky number 44 and see what turns up. Don't really want to go with magnum primers, although there is a gun show this weekend I might pick up some Varget to try out, it seems pretty versatile. Never used it before but there are tons of load data for the rounds I shoot that also indicate Varget. I want my H-4895 for the SKS rounds I shoot, so .......well thinking out loud now....Might get a pellet gun, they make some 45 cal. that you can use pistol bullets in....cooolll Thanks guys....I welcome any more comments on the subject. Oh and I did check my scope mounts, the thread lock is still tight, so i guess it's still got a good grip. Also when I was shooting the other day, I shot some Noslers that went haywire then changed over to the 150gr Hornadys and they were spot-on still.

 

[NCsmitty]

Welcome to THR, Suzanne.

rcmodel gives good advice and I concur with using H4895 at the 44gr starting load with the 180gr Nosler. I've used H4895 in my own 8x57 as well as Varget.

Good luck.


NCsmitty

 

[Suzanne]

So NCsmitty tell me about your loads for H-4895 and Varget! Please Please

 

[NCsmitty]

Sorry to say that I'm not at my house tonight. I'll try to remember to get it tomorrow when I go home.


NCsmitty

 

[NCsmitty]

Suzanne, I checked my data and I have loaded and shot 47gr of Varget behind a Hornady 170gr RN out of my 23" Mauser at a disappointing 2390fps. I would have thought that I would break 2500fps, but it didn't.

The same charge of H4895 should get me over that, but have not shot any for velocity yet.

The rifle is a converted Turk Mauser to which I fitted a Swedish commercial small ring 8x57 barrel with a fresh chamber.


NCsmitty

 

[Suzanne]

NCsmitty Thanks, I'm shooting a 8mm Yugo m24/52c,(formerly a CV 24) large ring, 23" barrel. I was thinking of switching to Varget, your findings and RCModel's suggestions make me want to try the H4895. There is a gun show this weekend where I can usually find some powder....hmmm what to get....the Hodgdon data I have indicate for your 170gr RN, a load from 43gr Varget @ 2362fps to 50.5gr @2700fps..Yeah I would think you would have gotten to at least 2500fps. The H4895 indicates from 40gr @2306fps to 49gr @ 2769fps.

 

[NCsmitty]

Your 24/52c is a nicely machined Mauser and is a desirable rifle.

Here's a link to some real world loads but approach with a little caution as they are full power loads.

http://www.realguns.com/loads/8x57mmjs.htm

I think that your problem using Win 748 has more to do with not using Magnum primers, and low weight charges, giving you erratic loads.
The consensus is to use magnum primers with all ball or spherical powders, and standard primers with extruded or flake powders.
That does not preclude you from using magnum primers working up a load from scratch using extruded powders, it's just not needed.
The exception is using some Winchester primers that do not offer a magnum version.


NCsmitty

 

[Suzanne]

NCsmitty; so actually I should be doing the opposite of my original intention, I should actually save the H4895 for the 8mm Nosler rounds and use the Win 748 for the SKS rounds I reload. Win seems to work fine in the 7.62x39. Or again I can try out some Varget, which the Hornady book says is a winner to use. I didn't know that about using magnum primers for the ball powder. Thanks, I looked over the loads from realguns.com and they indicate CCI250 on Win, BLC2 and RS TAC (which I've never heard of). I need to stick with extruded, I have about 950 CCI200 and don't wanna buy any more for now. Thanks again you've been a great help! Yeah I like the Yugo Mauser, I put a scout scope on it because it seems so accurate I felt it deserved some shooting time. I want to go deer hunting with it this year instead of using my old standby favorite Savage 30-06 (which is equally as wonderful). Possibly go elk hunting next year, it's a matter of getting the time off at the right time of year. You need a bit of time on hand to find elk, and a good buddy or two or three or four to help out. So the Winchester primers are good either with ball or extruded? What do you know about Varget, it seems to be used for every bullet size from 150-200gr?

 

[NCsmitty]

Varget works well with a wide spectrum of cartridges. It is very versatile, and I've used it with great success. I believe my use in the 8x57 will require me to raise the charge closer to maximum. At this time, I need to shoot the H4895 to see what potential it has.
Personally, I only use Winchester 209 primers in my shotshells. I use CCI primers exclusively in my brass cases.
Keep us posted as you progress.


NCsmitty