230Gr Berger Hybrid Seating Depths for 300WM

[SpartanDieselTech]

Hoping to get some input from other users on seating depths for the 230Gr Berger Hybrids in a 300 Win Mag.

All my previous experience with reloading has been with tangent ogives, and I have none with VLD's and/or Hybrids. It is my understanding that the Hybrids aren't as depth sensitive as the VLD's, however I'm looking for some places to start.

Rifle is an Accuracy International PSR. Currently shoots 1/2moa with FGMM 190 SMK loads, and with my handloaded "duplicate" with the same projo's and cartridge OAL. Are you guys who are using the Berger hybrids seeing any trends as to where these projo's favor the best accuracy? Obviously it will vary from weapon to weapon, but any user input is appreciated. Thanks.

 

[Aimsmall55]

I've played with the AI PSR and was hired to do load development for the .338 and .300 win mag bbls. I ABSOLUTELY could not get it to shoot the 208 amax, 210 vld. I tried different seating depth, h1000, r22, h4831sc, h4350, ect ect. The ONLY thing that would absolutely HAMMER was the 190 smk. I think that the win mag set up was designed for the 190's. If I remember correctly its a 1:11 twist?? The only reason I mention this is the 230 Hybrid is harder to tune than say the 230 otm. it's 1.660" long, so mag feeding is probably not gonna happen. If I were you, I'd get the 230 OTM and shoot those with about 75 to 76 grains of Retumbo. You can jump the hell out of those and they are about 60/1000's shorter. So, in a nutshell , give it a go, but load close to the lands, ( 35/1000"s off is the sweet spot for me) with the 230 hybrids.
Good luck.

 

[trauma1]

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Trauma1

 

[SpartanDieselTech]

I've played with the AI PSR and was hired to do load development for the .338 and .300 win mag bbls. I ABSOLUTELY could not get it to shoot the 208 amax, 210 vld. I tried different seating depth, h1000, r22, h4831sc, h4350, ect ect. The ONLY thing that would absolutely HAMMER was the 190 smk. I think that the win mag set up was designed for the 190's. If I remember correctly its a 1:11 twist?? The only reason I mention this is the 230 Hybrid is harder to tune than say the 230 otm. it's 1.660" long, so mag feeding is probably not gonna happen. If I were you, I'd get the 230 OTM and shoot those with about 75 to 76 grains of Retumbo. You can jump the hell out of those and they are about 60/1000's shorter. So, in a nutshell , give it a go, but load close to the lands, ( 35/1000"s off is the sweet spot for me) with the 230 hybrids.
Good luck.

It was my understanding initially that the twist was 1:11, which was making me skeptical. When I called Mile High (whom I purchased the rifle from) they said 1:10.

Spent some time today with a cleaning rod, marker, and masking tape to verify, and it is actually 1:10. Not sure when this changed, but this particular barrel is 1:10 for the Win Mag.

I seated a few bullets directly onto the lands (actually a couple thousands interference) using some fresh torn-down FGMM (don't have my dies set up yet) and they actually do fit in the mag, much to my amazement. I was completely with you on expecting them not to fit, but there is actually still a little bit of room. I'll snap some pictures of the results later.

I have Retumbo, H1000, 4350, RL22 and RL25 on hand, so I'll play around with those and various seating depths as time allows this week to get some brass processed. I may even tear apart a few boxes of FGMM 190's and use those since I've already established that those loadings (and correspondingly, brass) perform magnificently in the rifle.

Would anyone happen to know what powder is used in the FGMM 190SMK loads? It is 71.5 grains of *something*.

 

[Painless300]

I've played with the AI PSR and was hired to do load development for the .338 and .300 win mag bbls. I ABSOLUTELY could not get it to shoot the 208 amax, 210 vld. I tried different seating depth, h1000, r22, h4831sc, h4350, ect ect. The ONLY thing that would absolutely HAMMER was the 190 smk. I think that the win mag set up was designed for the 190's. If I remember correctly its a 1:11 twist?? The only reason I mention this is the 230 Hybrid is harder to tune than say the 230 otm. it's 1.660" long, so mag feeding is probably not gonna happen. If I were you, I'd get the 230 OTM and shoot those with about 75 to 76 grains of Retumbo. You can jump the hell out of those and they are about 60/1000's shorter. So, in a nutshell , give it a go, but load close to the lands, ( 35/1000"s off is the sweet spot for me) with the 230 hybrids.
Good luck.

Not sure why your 300 doesn't like anything over 190s but mine absolutely loves 208 A-max seated .05 off the lands, I had a lot of trouble at firstwith Berger 210 VLD Hunting but I finally found the magic depth of .002 off the lands running Fed 215 primers and 75g of H1000, now they are shooting sub qtr in.
I will say 200g Accubonds will not shoot better than 1-1/2 but I did get 180g Barnes TSX down to 3/8" groups but the copper clean up is a royal pain. My rifle is a hunting rig with a #3 Bartlein barrel so I mainly use hunting rounds.

To the OP:
I have learned that you need to start your load development with seating depth as close to the lands as possible, start your powder charge low and work up then once you find a decent powder and charge fine tune it by backing off the lands this way you know your load is safe to start with.

 

[Aimsmall55]

Not sure why your 300 doesn't like anything over 190s but mine absolutely loves 208 A-max seated .05 off the lands, I had a lot of trouble at firstwith Berger 210 VLD Hunting but I finally found the magic depth of .002 off the lands running Fed 215 primers and 75g of H1000, now they are shooting sub qtr in.
I will say 200g Accubonds will not shoot better than 1-1/2 but I did get 180g Barnes TSX down to 3/8" groups but the copper clean up is a royal pain. My rifle is a hunting rig with a #3 Bartlein barrel so I mainly use hunting rounds.

To the OP:
I have learned that you need to start your load development with seating depth as close to the lands as possible, start your powder charge low and work up then once you find a decent powder and charge fine tune it by backing off the lands this way you know your load is safe to start with.

Are you talking about the AI PSR??

 

[Aimsmall55]

Sorry read wrong. The rifle in question was developed for military use. It was designed to have a 3 bbl rifle in one. 3 bolt shrouds and 3 bbls all for the .308, .300 win mag, .338 lapua. The point is that the rifle was more designed for what the military was using as far as sniper ammo. Which for the .300 win mag would have been the 190 smk. But now that the op figured out that its a 1:10 twist , I feel it could probably work. OP, have you thought about the 215 hybrids?? The bearing surface is very little and you can have them ZOOMING. Very good bullet. Come to think I did have one successful load with the 210 vld. I was pilfering through my data books and remembered it.



This was the ONLY load above the 190 that shot. Nosler brass, fgm215m , Berger 210 vld.

 

[Aimsmall55]

This is all I could get with the 208 amax. Everything I tried was about like this.


Man, I miss playing with that rifle. Other than the 100# case... It was cool as hell.