Accuracy issues with a custom 338 Laupa
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snowpro440
Well-Known Member
Have you tried H-1000, and fed mag match primers, with lapua brass, and SMK's loaded just touching the lands with 89 grs moving up a half a grain at a time. It will come together . Try slowing down on moving the bullet too much Keep trying.
406precision
Well-Known Member
Try h1000 and 300 grn smk 89-90.5 ought to shoot i have a one 338 lapua from smr and one being delivered this week accuracy should not be an issue the one i have shoots .25 and the one im picking up dhot .38 with factory ammo during test fire
406precision
Well-Known Member
steeltraps
Well-Known Member
I have a 338 lapua and a 338 lapua imp. and both rifles DO NOT like Retumbo. That is strange i know, but true. My new 338 lapua imp. shoots 300 otm bergers 1/4 moa with h-1000 at 2950 fps. 300 otms at 3025 fps RL=33 at a little less than 3/8 moa. Now retumbo= 3/4 moa 3 shot groups and 7/8 moa 5 shot groups! I have 9 lbs or more of this stuff and it want shoot! Try RL-25, RL-33, H-1000 and VV 560.
Well there might be some light here for me in this tunnel. Here is today's results after taking in your guy's advice and Greg's over at SMRs. All loads were done to be kissing the lands.
Loads from left to right
H-1000 89.5gr, 300gr SMK, 3.984 COAL
H-4831SC 78gr, 300gr SMK, 3.984 COAL
H-869 102gr, 300gr SMK, 3.984 COAL
2nd Row
H-1000 89.5gr, 300gr Berger OTM, 3.982 COAL
H-4831SC 78gr, 300gr Berger OTM, 3.982 COAL
H-869 102gr, 300gr Berger OTM, 3.982 COAL
3rd row
H-1000 95gr, 250gr SMK, 3.974 COAL
H-1000 89gr, 285gr Horandy match BTHP, 3.985 COAL
H-1000 89gr, 280gr LRX BT, 3.985 COAL
As you can see from the photos the H-4831SC with the 300gr SMK did the best.This rifle is nowhere near where it should be for groups at 200 yards though. I'm going to work a bit more with the SMKs in this powder and see. Though i'm not happy about the powder itself, sticky bolt at 78grs and averaging only 2500fps... Also I have never worried to much about primers, have people seen large differences between primer selections? I haven't been able to find any Federal 215s, and am still using the Remington 9 1/2s.
Loads from left to right
H-1000 89.5gr, 300gr SMK, 3.984 COAL
H-4831SC 78gr, 300gr SMK, 3.984 COAL
H-869 102gr, 300gr SMK, 3.984 COAL
2nd Row
H-1000 89.5gr, 300gr Berger OTM, 3.982 COAL
H-4831SC 78gr, 300gr Berger OTM, 3.982 COAL
H-869 102gr, 300gr Berger OTM, 3.982 COAL
3rd row
H-1000 95gr, 250gr SMK, 3.974 COAL
H-1000 89gr, 285gr Horandy match BTHP, 3.985 COAL
H-1000 89gr, 280gr LRX BT, 3.985 COAL
As you can see from the photos the H-4831SC with the 300gr SMK did the best.This rifle is nowhere near where it should be for groups at 200 yards though. I'm going to work a bit more with the SMKs in this powder and see. Though i'm not happy about the powder itself, sticky bolt at 78grs and averaging only 2500fps... Also I have never worried to much about primers, have people seen large differences between primer selections? I haven't been able to find any Federal 215s, and am still using the Remington 9 1/2s.
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It looks like you are shotgunning your load development with different powders and hoping to get lucky and find a load. Why don't you take one powder and one bullet (my choice would be H1000 and the 300 gr Berger OTM or elite hunter) and start around 87 gr and work your way up in .5 gr increments until you see pressure signs which will probably be around 92-92.5 gr. Shoot the loads at 200-300 yards. Take the best out of the group and play with the seating depth if you are not happy with the group size yet.
(I Havnt read all the posts so if you have already done this..sorry)
H4831SC is not an ideal powder for this cartridge.
(I Havnt read all the posts so if you have already done this..sorry)
H4831SC is not an ideal powder for this cartridge.
Bullet bumper
Well-Known Member
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- May 20, 2009
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Put an Atlas bi-pod on the rifle before you go bankrupt paying for the ammo.
This is no way to tune a load in to a particular gun.
Sand bags are a bad way to support a heavy recoil gun .
You may have shot at jnr Olympic level but was it with a 338 lapua. Are you experienced in handling big recoil ?
Take a video of you shooting and I bet we can pick up , bad support system and failure to control recoil .
From the changing verticle and horizontal spread of the groups , I see poor consistancy in shot to shot delivery .
Hell I see videos of proffesional snipers that can't control recoil well and others that stay rock solid and hardly move at all behind the same gun .
I could be wrong but that is what i see in the groups.
This is no way to tune a load in to a particular gun.
Sand bags are a bad way to support a heavy recoil gun .
You may have shot at jnr Olympic level but was it with a 338 lapua. Are you experienced in handling big recoil ?
Take a video of you shooting and I bet we can pick up , bad support system and failure to control recoil .
From the changing verticle and horizontal spread of the groups , I see poor consistancy in shot to shot delivery .
Hell I see videos of proffesional snipers that can't control recoil well and others that stay rock solid and hardly move at all behind the same gun .
I could be wrong but that is what i see in the groups.
Thank you for the replies, this is my first heavy recoil rifle other then a factory 7mm rem mag. I have never heard that sandbags are a bad way to support a heavy recoil rifle. Is a bipod typically the best bet then? Why don't you want to use a two bag system?
After doing some more research on recoil management the light bulb is going off a bit. I learned to shoot with minimal pressure but firm positioning on the weld, shoulder and grip. Seems I want strong positive pressure here instead. The relaxed method I have been using I lose my sight picture with every shot making follow through impossible which should of set the alarms off earlier.
After doing some more research on recoil management the light bulb is going off a bit. I learned to shoot with minimal pressure but firm positioning on the weld, shoulder and grip. Seems I want strong positive pressure here instead. The relaxed method I have been using I lose my sight picture with every shot making follow through impossible which should of set the alarms off earlier.
Bullet bumper
Well-Known Member
- Joined
- May 20, 2009
- Messages
- 1,045
Heavy recoil rifles pound into the bags and constantly change the support the rifle sees on subsequent recoil tracking. Sure a sand bag can be used to shoot any gun so can an old rotten log but is it the best support possible well no . A bi-pod is not perfect either but it's way more consistant than sandbags I have found .
You can't shoot a 338 lap like a 6mm BR target rifle it don't work well.
Firm up the grip and try to reduce the recoil movement as much as possible .
Preload the bi-pod by pushing forward slightly at the shoulder before each shot and then steady for the actual shot .
Bi-pods tend to give good vertical control but can skate about from side to side making groups a bit horizontal at times . That is why it's important to not let the gun move too far back each time as it allows the bipod to track sidways if one foot grips more than the other and or the butt of the stock is allowed to slop about on the shoulder . A bunny ear leather or cordura rear bag might be better also than a rear sandbag depending on the stocks design which I have not seen .
Pick the best load so far and stick with that for a while untill you work out how the gun likes to be driven because they do vary a bit in how they like to be held , fired and controled . I reckon you will see those groups tighten up and then you will be able to tune a load better .
You can't shoot a 338 lap like a 6mm BR target rifle it don't work well.
Firm up the grip and try to reduce the recoil movement as much as possible .
Preload the bi-pod by pushing forward slightly at the shoulder before each shot and then steady for the actual shot .
Bi-pods tend to give good vertical control but can skate about from side to side making groups a bit horizontal at times . That is why it's important to not let the gun move too far back each time as it allows the bipod to track sidways if one foot grips more than the other and or the butt of the stock is allowed to slop about on the shoulder . A bunny ear leather or cordura rear bag might be better also than a rear sandbag depending on the stocks design which I have not seen .
Pick the best load so far and stick with that for a while untill you work out how the gun likes to be driven because they do vary a bit in how they like to be held , fired and controled . I reckon you will see those groups tighten up and then you will be able to tune a load better .
snowpro440
Well-Known Member
+1 Bullet bumper and what Korhil78 said ..............
Most importantly get solid on your rest and setup every time the same. Measure each bullet ogive to base of the case. Load 3 rounds and shoot at a time letting the barrel cool between groups. Start with the powder weight change first then after you find a good group then work on seating depth. Best of Luck and keep us posted
Most importantly get solid on your rest and setup every time the same. Measure each bullet ogive to base of the case. Load 3 rounds and shoot at a time letting the barrel cool between groups. Start with the powder weight change first then after you find a good group then work on seating depth. Best of Luck and keep us posted
Alright guys, quick update and i'm a bit more pleased. I moved to the ground with a bipod and bunny ears rear bag. Also moved from 200 yards to 137( only dry spot in the field).
Using H-1000, 300gr berger hunters, win mag primers and seated to my max magazine length. My best groups were with 88.5 grains(top right), and 89.5 grains(middle right). As you can see I typically had one flyer. The thing that bothers me though is that I only called the flyers about half the time. I'm also still having problems with the follow through, IE losing the target temporally after each shot.
Also I'm getting a heavy bolt lift even with my lightest of loads, but maintains this heavy lift to my max loads? No other pressure signs though.
Thank for all the help guys, this recent outing gives me hope!
Using H-1000, 300gr berger hunters, win mag primers and seated to my max magazine length. My best groups were with 88.5 grains(top right), and 89.5 grains(middle right). As you can see I typically had one flyer. The thing that bothers me though is that I only called the flyers about half the time. I'm also still having problems with the follow through, IE losing the target temporally after each shot.
Also I'm getting a heavy bolt lift even with my lightest of loads, but maintains this heavy lift to my max loads? No other pressure signs though.
Thank for all the help guys, this recent outing gives me hope!
