Working up a load for my G98/40.

[Gunnut 45/454]

Being it was Veterans day weekend I got to thinking about Dad and since he gave me these G98/40's when he passed I hadn't worked up a load using these 205 gr NEI boolits! So I loaded up 10 to see what they'd do. I got this mold for my K98 cause it absolutely hated the Lee 175 gr cast boolits. Anyway I went out to day after getting the COL as close to the lans as possible. I shot this group with it at 70 yards to make sure it was on paper before I went to 100 yards. This absolutely the best group I've shot with this gun though it shoots just about everything I've shot through very well. :)

I was disappointed when I went out to 100 yards- I'm quite sure the load was just to slow-1500 ish FPS to keep these big bullets stabilised. Next load will be 22.5 gr IMR4198 and should push these to around 1700 fps. I want an easy on the shoulder target round as these 205 are pretty hard on the shoulder at 2200 FPS or more.

[Gunnut 45/454]

Update with IMR4198 load. Since I was at near max load with the Unique I switched to the IMR 4198. I wanted more speed and the starting load (22.5 gr)would get me to around 1700 fps. I was right the Unique load was to slow as you can see with the target below. With the Unique load I had a shotgun pattern with only two strikes on the target. Once I dopped the wind I got a fair group. Next load will be .5 gr more 23 gr I think just alittle more speed will help tighen the groups some more.:-D:-D

[leadman]

Looks like the load is improving. If you have some SR4759 you might want to try it.

I have very good accuracy with the Lyman 160gr Loverin boolit in the 8X57 and 8X58R. I also shoot a Lee Karabiner from an early single cavity that runs around 235grs. It does well but like the lighter boolit better.
Have you tried slightly engraving the boolit into the rifling? I do this with a couple of rifles that have long throats and have to single load as the cartridge won't fit in the magazine, but accuracy is improved.

[Gunnut 45/454]

leadman
I agree but unlike my K98 these G98/40's have a shorter throat. At 2.950" I'm about .010" off the lans. My first load I loaded them way short and accuracy was terrible! These also like the 175 gr Lee cast where my K98 will not shoot them at all -can't load them long enough in the K98 where I can get them to the lans in the G98/40. I get these 205 gr NEI to drop out at 233 +/- a gr. Unfortunately I don't have /nor can I find that SR4759 around here. I do have some H380 that my Lyman Manual lists. I think I'll use up this IMR 4198 as it never gave me good groups in any other caliber I used it in with cast or Jwads.

[leadman]

Will the cartridge fit in the magazine if you load longer? Sr4759 is not a real popular powder due to the way it flows thru a measure. I weigh all my charges with this.

This is part of the fun of reloading with cast, chasing the groups.

[Gunnut 45/454]

leadman
Yep I have room in the mag but the alcove of the bullet does not allow longer COL as it will be forced into the rifling. As I said before I got them about .010" off the rifling. When making up a dummy it forced the bullet in with contact to a COL of 2.960" Therefore my load col of 2.950".

[Larry Gibson]

Gunnut 45/454

I want an easy on the shoulder target round as these 205 are pretty hard on the shoulder at 2200 FPS or more.

2200+ fps from the 8x57 with a with a 205 gr cast bullet is not difficult. Problem is you are using the wrong burning rate of powders. Suggest you switch to 4895 as the fastest and try H4831SC, AA4350, RL19 or RL22. Alsowith the Mauser's 9 1/4 - 9 1/2" twist accuracy will get "iffy" unless all is done right by you in casting and loading above 1900 fps.

Also, recoil is basically a function of rifle weight, bullet weight and velocity. The rifle weight is fixed, if you use the same mould the bullet weight is fixed so if you increase velocity then the recoil is also increased. You must decrease velocity, bullet weight or both to have a "I want an easy on the shoulder target round ".

Suggest a Lyman 323470 Lovern style bullet with Unique or 4198 at 1500 - 1850 fps for a load more comfortable on the shoulder......probably more accurate too.

BTW; I've loaded 210 gr cast in the 8x57 down to 500 - 600 fps and they are stable to 200+ yards. Your accuracy problems with the 1st load was simple too fast a powder for the velocity. Your load with the 4198 should be a better load than the Unique load. I suggest a 1/2 gr dacron filler to make it more consistent in ignition and thus more accurate down range.

Photo shows a 10 shot group at 100 yards with my 323471 (210 gr) loaded over 31 gr 4895 with a dacron filler out of my 24/47 Mauser. Top two were fired then the scope adjusted as I was aiming at the bottom diamond. There's 8 shots in that group. Velocity of 1865 fps is listed on target. The ES was 18 fps withan SD of 7 fps. The recoil is quite manageable.

Larry Gibson

[Gunnut 45/454]

Larry
I agree, I maybe reinventing the wheel here but thats the fun of load developement. As I said I had worked up a good load for my K98 with this bullet but cause of the difference with COL between the two guns I never settled on a load for the G98/40's. This what happens when you got to much time on your hands. I'll have to look at my notes but I do believe the K98 load is either on H or IMR4895.

[Larry Gibson]

Yup, I certainly do agree that the load development is fun for many of us. It can also be quite frustrating for those who have a goal and are using the wrong components to get there. That looks to be a fine Mauser and since it was passed on by your Dad I appreciate your efforts to get them shooting well. That NOE bullet should be a very good one, especially in the 1800 - 1900 fps range, with a medium or slow burning powder. Keep us posted on your trials and tribulations to get her shooting well, be glad to help where ever I can.

Larry Gibson

[Gunnut 45/454]

Larry G
Well you can say I told you so! Shot the IMR 4198 loads today- and as normal the 4198 disappointed with a shotgun pattern group! Next load is going to be 31 gr IMR 4895 ! If it's nice enough tomorrow it will get shot! I'll be working the 8x57 loads as I'm awaiting the gaschecks for the .223 Rem bullets!

[Larry Gibson]

Ah yes, sometimes we live and learn. But what the heck, you were shooting a very nice rifle so the "learning" couldn't have been all that bad;-)

Larry Gibson

[303Guy]

It wouldn't be fun if it all went smoothly and easily. We wouldn't get to chat with you either.

Larry nailed it when he said those boolits will stabilise at slow speeds. Speed does not effect boolit stability much. It does close to the sound barrier and apparently it does up and beyond 3000fps where stability increases and subsonics need a tad more twist rate they say. But for us, speed does not change stability noticeably. So they say!

My question is; what is actually going on when more speed improves accuracy? Did I just say boolit speed?:roll: (The direction of a boolit really has no bearing :mrgreen:).

[Gunnut 45/454]

I'm no bullet god , but over the years I've learned a few things! Every rifle has a sweet spot as in bullet wt and velocity! I have found this spot in almost every rifle I own . I'm just now getting to this rifle with the heavy wt cast bullets already found it for Rem 185 gr, Privi 198 gr and Lee cast 175 gr . And as Larry G has pointed out it's been with Moderate burn rate powders and less then max velocity. Why this is I have no clue but its fact they work! As we well know the twist rate does effect how our rifles shoot as well. Some twist rates just will not produce good groups with cast. Some just surprise the heck out of us -like my Colt match target 1:7" shoots better then my 1:9" when using 22LR Conversion kit! Now with a load of 18gr H4895 under a 55gr Cast gc bullet I get pretty much the same accuracy with a slight edge to the 20" 1:7" over th 16" 1:9" and I do believe it's because of the velocity increase, maybe the increased RPM?
The only rifle I found this not to be true with is my 30-30 and the LEE 170gr GC I actually run these faster then factory 170gr loads with great accuracy in a micro grooved barreled Marlin. Go figure! :)

[Gunnut 45/454]

Larry G
Wel I shot the 31 IMR4895 load- seemed pretty fast and group was so so! I'm going to try 30gr
I think the 31 was up there in high 1900 maybe close 2000 fps! Recoil was pretty stiff not abusive but noticeable! The quest continues! :)

[Larry Gibson]

Drop the 4895 to 28 gr with a 1/2 - 3/4 gr dacron filler and work up in 1/2 gr increments. What alloy are you using?

Larry Gibson

[Gunnut 45/454]

Larry G
WW water quenched! Adding some sodder( 95% tin 5% silver) to help fill out the molds!