I tried the flat spot load development

[hunter24605]

This is very interesting to me. Thanks for posting and I will have to try this out! I assume it comes with a few caveats like requiring a very good quality chronograph and meticulous attention to detail in loading to help minimize velocity spread on any given charge to prevent false data. But anybody trying to squeeze out every bit of potential from a rifle should already have those two items covered.

 

[SJB358]

Jim.... that's a great shooting 7 Mag you have. I used this method for the 154 Interbond and am getting about 3260 with it. Gotta love it.

did you get good results with the interbond ? how far are you jumping them ? with this velocity it must be your 7mm MSM . the interbond at that speed , holly cow what a combo .

I worked around .050" off for quite a few groups. The last time out i shot 3 groups varying seating depth a little. None of them did what I wanted. On a hunch I'd loaded the same charge but backed it up .100" and it plunked 3 into 3/4"s.

I think it's going to be a shooter. I like the bullet a lot.

 

[jimbires]

Jim.... that's a great shooting 7 Mag you have. I used this method for the 154 Interbond and am getting about 3260 with it. Gotta love it.

did you get good results with the interbond ? how far are you jumping them ? with this velocity it must be your 7mm MSM . the interbond at that speed , holly cow what a combo .

I worked around .050" off for quite a few groups. The last time out i shot 3 groups varying seating depth a little. None of them did what I wanted. On a hunch I'd loaded the same charge but backed it up .100" and it plunked 3 into 3/4"s.

I think it's going to be a shooter. I like the bullet a lot.

it seems all these bonded bullets like to jump , just like mono's. man that bullet expanding to about .750" , and being pushed at 3260FPS . that's an animal stopper for sure .

 

[desertcj]

This is a nice method. It's basically a ladder test except you are using the chrono readings instead of the small vertical group on the target.

 

[Wis65x55]

This is very interesting to me. Thanks for posting and I will have to try this out! I assume it comes with a few caveats like requiring a very good quality chronograph and meticulous attention to detail in loading to help minimize velocity spread on any given charge to prevent false data. But anybody trying to squeeze out every bit of potential from a rifle should already have those two items covered.

1. I would only use high quality brass that is weight sorted. 2. If possible, I would weigh the powder charge on two scales.
Keith

 

[SJB358]

Jim.... that's a great shooting 7 Mag you have. I used this method for the 154 Interbond and am getting about 3260 with it. Gotta love it.

did you get good results with the interbond ? how far are you jumping them ? with this velocity it must be your 7mm MSM . the interbond at that speed , holly cow what a combo .

I worked around .050" off for quite a few groups. The last time out i shot 3 groups varying seating depth a little. None of them did what I wanted. On a hunch I'd loaded the same charge but backed it up .100" and it plunked 3 into 3/4"s.

I think it's going to be a shooter. I like the bullet a lot.

it seems all these bonded bullets like to jump , just like mono's. man that bullet expanding to about .750" , and being pushed at 3260FPS . that's an animal stopper for sure .

I believe it's time to take it out long now. Gotta anneal, tumble and reload but I think I'm good.

 

[jimbires]

let me know how it shoots at longer distances .

 

[jimbires]

I worked two more loads using this flat spot method . both are in my tikka 7mm-08 . I used RL17 powder , first time in this rifle . I used my stand by 139 BTSP bullet and also the 139SST . I've played with the SST in the past , but wanted to give it a try again .

here is my velocity chart for the BTSP bullets . I loaded at 49.1 gr .



my SSt velocity chart , I loaded 48.8 gr



I had a couple bullets hit a steel I beam I had my cardboard hung over .



here are the targets of different seating depths . the SST holes are taped over , the BTSP holes are not .

 

[jimbires]

sorry guys , I have a heck of a time with posting pics now . I think I'll give up on this posting .

 

[RaySendero]

Did I miss it?

What distance are you shooting?

 

[Dwh7271]

Top pic looks like about 1/2 inch Jim.
Nice.

 

[hseII]

I worked two more loads using this flat spot method . both are in my tikka 7mm-08 . I used RL17 powder , first time in this rifle . I used my stand by 139 BTSP bullet and also the 139SST . I've played with the SST in the past , but wanted to give it a try again .

here is my velocity chart for the BTSP bullets . I loaded at 49.1 gr .

View attachment 5

my SSt velocity chart , I loaded 48.8 gr



I had a couple bullets hit a steel I beam I had my cardboard hung over .

View attachment 3

here are the targets of different seating depths . the SST holes are taped over , the BTSP holes are not .

View attachment 2

View attachment 1

Looking Great.

That's amazing velocity for a 7-08.

 

[jimbires]

these are from 100yds .

the top target has three holes not taped , the BTSP bullets , is about 1/2 inch .

the middle target has three holes taped over , that I outlined with an ink pen . these are the SST bullets . these are about 3/4 inch .


I had a rough time shooting yesterday . I just could not get my head in the game .

with hunting season getting close this method might help out a guy that needs to get a new rifle shooting decent quickly . I seem to be having good luck using this velocity method . I've played with four different combo's in two different rifles , and have ended up with under an inch at 100 yards on all of these . it's a very fast way to try and get a decent shooting load . I'm sure all these could be fine tuned more . I feel a hunting rifle that's able to shoot an inch, or smaller , at 100 yards will take a lot of game .

 

[Cleveland48]

It is a very quick method to finding a good load. Whole lot cheaper too!


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[SJB358]

these are from 100yds .

the top target has three holes not taped , the BTSP bullets , is about 1/2 inch .

the middle target has three holes taped over , that I outlined with an ink pen . these are the SST bullets . these are about 3/4 inch .


I had a rough time shooting yesterday . I just could not get my head in the game .

with hunting season getting close this method might help out a guy that needs to get a new rifle shooting decent quickly . I seem to be having good luck using this velocity method . I've played with four different combo's in two different rifles , and have ended up with under an inch at 100 yards on all of these . it's a very fast way to try and get a decent shooting load . I'm sure all these could be fine tuned more . I feel a hunting rifle that's able to shoot an inch, or smaller , at 100 yards will take a lot of game .

I'd bet a 100 dollar bill if your rifle isn't sick and you're loading fairly straight rounds yiu can have your load work done in under 30 rounds. So far it's been a cinch.

 

[Cleveland48]

I agree 30 rounds should be plenty.


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[jimbires]

I agree too fellas , it almost seems to easy .

 

[jimbires]

Looking Great.

That's amazing velocity for a 7-08.

I have a 24"bbl 7mm-08 that I shoot Berger 140 hunting VLD's , with RL17 . I get 3080FPS . excellent accuracy , no pressure signs , and great brass life . RL17 was made for the 7-08's .

 

[AZ Wildcat]

New to this forum but I've been following this thread with interest. When running your initial velocity test are you just firing one round per load (ie a total of 10 shots)?


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[jimbires]

New to this forum but I've been following this thread with interest. When running your initial velocity test are you just firing one round per load (ie a total of 10 shots)?


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yes , that is correct .


welcome to the forum , AZ Wildcat .