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338 Lapua Ackley Improved Loads.
- Thread starter Sierra’1
- Start date
I just tested a .366 bushing and the pressure signs are still there in the 102 grain range
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You should get that rifle to a good shop with even better measuring equipment. Something is very wrong here.
You should get that rifle to a good shop with even better measuring equipment. Something is very wrong here.
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One idea from an old timer was there could be a ring of carbon buildup around the neck that causes overpressure. He also asked me about my RL 33 powder, he has witnessed himself and others that I’ve gotten lots that are hotter then normal. He recommend taking JB bore paste to the throat and then switching to N170 powder. Thought?
Anyone have experience with that powder?
One idea from an old timer was there could be a ring of carbon buildup around the neck that causes overpressure. He also asked me about my RL 33 powder, he has witnessed himself and others that I’ve gotten lots that are hotter then normal. He recommend taking JB bore paste to the throat and then switching to N170 powder. Thought?
Anyone have experience with that powder?
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Vihtavuori n570 is just a bit slower burning than RL33; it's a double-based n170. Please communicate with the barrel manufacturer/gunsmith/source of this rifle. You're taking some unnecessary risks that could result in a most unpleasant manner--to you and/or someone else. Everyone responding to you means well, but sorry to say, none of the advice has solved the issues you're facing. I do wish you the best outcome...
Vihtavuori n570 is just a bit slower burning than RL33; it's a double-based n170. Please communicate with the barrel manufacturer/gunsmith/source of this rifle. You're taking some unnecessary risks that could result in a most unpleasant manner--to you and/or someone else. Everyone responding to you means well, but sorry to say, none of the advice has solved the issues you're facing. I do wish you the best outcome...
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I appreciate it, thanks
Vihtavuori n570 is just a bit slower burning than RL33; it's a double-based n170. Please communicate with the barrel manufacturer/gunsmith/source of this rifle. You're taking some unnecessary risks that could result in a most unpleasant manner--to you and/or someone else. Everyone responding to you means well, but sorry to say, none of the advice has solved the issues you're facing. I do wish you the best outcome...
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Is V570 still sold?
I haven't used it yet but Long Range Hunting forum had some guys using it w a 338 LM AI. I believe Broz did a workup w it along w RL-33.
Neither have I--and I do have 7+# of it--but did use it in another improved variant of the Lapua with a 36* shoulder (338 Terminator). Search this and other forums as there are many shooters who have considerable experience with it. I used it with 300 gn OTM Bergers. Please see attached initial workup of n570 in the foregoing rifle. Hope
While doing some development for the AI this week I did a quick weight consistency comparison between the .338 300g A-Tips and the 300g Berger OTMs. I used both a RCBS Load master and a classic beam scale for backup. I weighed 10 random bullets from each group. In summary the A-Tips were all overweight from .2 to .6 grains for each bullet with a total of 2.5 grains over weight across 10 bullets. To be honest I wasn’t expecting this because about seven years ago I weighed Berger OTMs in the same caliber/weight and they fluctuated much more. Berger must have improved their pouring/casting system:
300g A-Tips:
300.2, 300.5, 300.2, 300.2, 300.2, 300.6, 300.4, 300.3, 300.5, 300.4
300g Berger OTM Hybrids:
300.1, 300, 300, 300, 300.1, 299.9, 299.9, 300.1, 300, 300
Best I've gotten with the A-tips is a 5.6 SD with 104g RL 33, at an AVG of 2848fps with only four shots, so not a large test group.
On to test the Berger's today.
300g A-Tips:
300.2, 300.5, 300.2, 300.2, 300.2, 300.6, 300.4, 300.3, 300.5, 300.4
300g Berger OTM Hybrids:
300.1, 300, 300, 300, 300.1, 299.9, 299.9, 300.1, 300, 300
Best I've gotten with the A-tips is a 5.6 SD with 104g RL 33, at an AVG of 2848fps with only four shots, so not a large test group.
On to test the Berger's today.
Attachments
Just finished some load development. 300g Berger OTMs seem to be working a bit better than A-tips. Only a four shot group but there’s obviously a node.
105.5G RL33. 2911, 2909, 2916, 2908. Max 2916 Min 2909. AVG 2911 SD 3.4
105.5G RL33. 2911, 2909, 2916, 2908. Max 2916 Min 2909. AVG 2911 SD 3.4
Attachments
15 ish grains of bullseye, then to the top of the neck with the COW, then shredded cotton packed in to the neck. Ive used up to 20 grains before. Try one at the lower charge to be safe and verify it fireformed adequately
I fire form improved 338LM (338 Rogue 37° shoulder) using 25gr of Unique pistol powder topped with Cream of Wheat to the shoulder/neck junction then a wadd of toilet paper tucked inside the neck. I started at 18gr of Unique and increased in 1gr increments until I got good formation of the shoulder. 25gr was the sweet spot.
338 Lapua "Rogue" fully fire formed on left, middle is after 25gr of Unique and COW, and standard Lapua Mag on the right.
I referred Joden to my smith. Last we spoke, he said the new barrel fixed the issue.
I fire form with RL-33 at 95 grains Hornady 235 grain discontinued bullets (ballistic tip something or another). Then again with 105 grains. Both times seating bullets in the lands .01. Both loads shoot great and are cheap so no wasted shots.
338LM Improved, 250SMK, 215 primer, Lapua brass. No compressed loads.
110 grains RL-33 shoots well but barrel gets hot fast in just a few rounds.
99 grains H1000
Hammers!!!
102 grains H1000
Shoots just as good as 99 grains but has a slightly sticky bolt.
All bullets HBN coated, powder treated with Tubb dust. On my 7th reload with the brass. No annealing, primer pockets still good. Clay birds at 1100 are a joke. No clue as to the SD/ED spread.
Hope this helps
338LM Improved, 250SMK, 215 primer, Lapua brass. No compressed loads.
110 grains RL-33 shoots well but barrel gets hot fast in just a few rounds.
99 grains H1000
Hammers!!!
102 grains H1000
Shoots just as good as 99 grains but has a slightly sticky bolt.
All bullets HBN coated, powder treated with Tubb dust. On my 7th reload with the brass. No annealing, primer pockets still good. Clay birds at 1100 are a joke. No clue as to the SD/ED spread.
Hope this helps
i didn’t see any pressure signs at 102. Starting to see a bit flatter primers at 105.5 but nothing concerning. Bolt lift is normal. I’m on reload #4 with this lot of brass and the pockets are still good.
J
Finally loaded up the Warner Flatline 256 w N570. Ran it up to 3350 FPS w no signs of pressure.
I developed a really accurate load with Ramshot LRT over the summer, but it was rather anemic and in the end wasn't much of an advantage over vanilla .338LM. So recently I started over with RL33 and have come up with a much better load and confirmed at distance.
One of these is not like the other...
.338 LM Improved 40
Berger 300 OTM
Lapua Brass
CCI 250
106.3gr RL33
neck mandrel 0.3345" so fairly tight neck tension
3.881" COAL
3096fps AVG out of 36" barrel with ES 17
In confirmation, I couldn't get another near one-hole group, but a folllow-on five shot group was all touching. Also confirmed 13.1 mils to a mile.
One of these is not like the other...
.338 LM Improved 40
Berger 300 OTM
Lapua Brass
CCI 250
106.3gr RL33
neck mandrel 0.3345" so fairly tight neck tension
3.881" COAL
3096fps AVG out of 36" barrel with ES 17
In confirmation, I couldn't get another near one-hole group, but a folllow-on five shot group was all touching. Also confirmed 13.1 mils to a mile.
Does anyone have any good loads for a 338 Lapua AI with 300gr bergers?
I have RL26,h1000,and N570
I like to build a load from my RL26 but not sure if its going to be a little to fast for the 300gr bergers.
Thank you in advance for any information.
I have RL26,h1000,and N570
I like to build a load from my RL26 but not sure if its going to be a little to fast for the 300gr bergers.
Thank you in advance for any information.
RL26 is too fast. H1000 and N570 are doable, but not ideal because they're a tad fast for the 300s. They're great for 285s or similar solids. RL33 and LRT are much better options.
Looking at my old log book, back in 2014 I was shooting 300 Scenars with 102gr N570.
Here's what Quickload predicts:
Looking at my old log book, back in 2014 I was shooting 300 Scenars with 102gr N570.
Here's what Quickload predicts:
I found N570 to be fine for what your asking. I have used it across 4 separate 338AI in the 98 to 101 grain area. The 101 charge was with HBN coated berger 300 grain, 30” barrels and all ran around 2970-2990, touching to jumped at .050 off, 9.4 twist up to a slower 10 twist. All performed very well
As mentioned above, many have had success with RL33, Ive found no reason to leave N570
As mentioned above, many have had success with RL33, Ive found no reason to leave N570
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