300 Norma Improved 35 degree

[Tucker65]

Hornady might have a set also.

 

[Ledd Slinger]

Figured I'll update on some load speed workup data and a little hunting I've done so far this fall with my 300 NMI. Running a 27" Hart barrel with 10" twist on a BAT HR action in a Woox stock.

Ran the 230gr Berger against the 220gr Berger using N570 at varying seating depths. With the Hart barrel being fully broke in, the speeds with the 2 bullets were nearly identical. Was a little surprised at how the 230s are screaming down the pipe. Had one clicker with a slight ejector swipe on the 230s but no other rounds repeated that pressure sign so must have been an oddball piece of brass. All cases with 4 firings after this speed test measured out to having ZERO case head expansion against virgin case heads. All Lapua brass holding up very well.

Ended up going with the 220gr at 20 thou off for hunting this fall. Accuracy is around 3" at 800 yards from my bipod. Took an antelope buck at 505 yards quartering away while he was eating on a pile of spilled wheat grain. One shot face planted him right in his tracks and he didn't twitch once. Stone cold dead on impact. Dead before he even hit the ground. Vitals were completely and utterly destroyed and NO meat damage whatsoever. I believe this makes big game animal #7 that ive taken with the 220gr bullets. The 30 cal 220gr is hands down my favorite Berger hunting bullet to date

 

[Infrequent Shooter]

Figured I'll update on some load speed workup data and a little hunting I've done so far this fall with my 300 NMI. Running a 27" Hart barrel with 10" twist on a BAT HR action in a Woox stock.

Ran the 230gr Berger against the 220gr Berger using N570 at varying seating depths. With the Hart barrel being fully broke in, the speeds with the 2 bullets were nearly identical. Was a little surprised at how the 230s are screaming down the pipe. Had one clicker with a slight ejector swipe on the 230s but no other rounds repeated that pressure sign so must have been an oddball piece of brass. All cases with 4 firings after this speed test measured out to having ZERO case head expansion against virgin case heads. All Lapua brass holding up very well.

Ended up going with the 220gr at 20 thou off for hunting this fall. Accuracy is around 3" at 800 yards from my bipod. Took an antelope buck at 505 yards quartering away while he was eating on a pile of spilled wheat grain. One shot face planted him right in his tracks and he didn't twitch once. Stone cold dead on impact. Dead before he even hit the ground. Vitals were completely and utterly destroyed and NO meat damage whatsoever. I believe this makes big game animal #7 that ive taken with the 220gr bullets. The 30 cal 220gr is hands down my favorite Berger hunting bullet to date

View attachment 1490924
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View attachment 1490926View attachment 1490927

beautiful land, where? nice shooting too.

 

[scyzer]

Does anyone have any AZTEC codes for the cartridge and Peterson brass? I’m trying to not sacrifice a piece if possible.

 

[Ledd Slinger]

beautiful land, where? nice shooting too.

Thanks. Just wheat fields on the plains of Montana

 

[schw15]

Just getting my 300 norma improved 35. Has anyone used ramshot lrt 225 eldm to fireform?

Then my load will be with
n565 berger 220.
n565 250 a-tip.

 

[Ledd Slinger]

I use the 225 ELDM to foul and fireform just so I don't waste Bergers, but not Ramshot. I would fireform with the powder you plan on using. Will help you learn proper cleaning techniques because each powder can foul out and clean differently. N565 will probably be too fast for those bullets and N568 is too slow. N570 works very well for speed and accuracy on the 220gr and bigger bullets. Personally, I wouldn't waste my time on anything heavier than 230gr in the NMI. You want something bigger than 230gr, build a big 338 cal rifle

 

[scyzer]

Does anyone have any AZTEC codes for the cartridge and Peterson brass? I’m trying to not sacrifice a piece if possible.

Looking at the non fireformed 300NM parent case data on the Peterson Google Sheets document it seems like 0165-0170 is a reasonable range for 16 thou neck thickness. Can I confirm if anyone has any data?

 

[schw15]

I use the 225 ELDM to foul and fireform just so I don't waste Bergers, but not Ramshot. I would fireform with the powder you plan on using. Will help you learn proper cleaning techniques because each powder can foul out and clean differently. N565 will probably be too fast for those bullets and N568 is too slow. N570 works very well for speed and accuracy on the 220gr and bigger bullets. Personally, I wouldn't waste my time on anything heavier than 230gr in the NMI. You want something bigger than 230gr, build a big 338 cal rifle

I figured use the cheap stuff for fireforming and save the good powder.

 

[schw15]

What freebore specs do you guys go with on alex reamer I know he offers a few different options. Best freebore for 220 to 230 grain bullets

 

[Ledd Slinger]

What freebore specs do you guys go with on alex reamer I know he offers a few different options. Best freebore for 220 to 230 grain bullets

.225" works for 220gr. Maybe go .235"-.245" if you want to use the 230gr exclusively.

I originally did .235" on my first two NMI builds and found that after initial throat erosion of a 100 round barrel break in, I was a little longer than I wanted for the 220gr bullets. You'll get some decent growth initially, then it slows down once the lands is worn in. My current reamer has .225". So now once the barrel is broke in and has sped up for serious load development, I'm sitting right where I want to be for free bore on the 220s.

 

[schw15]

.225" works for 220gr. Maybe go .235"-.245" if you want to use the 230gr exclusively.

I originally did .235" on my first two NMI builds and found that after initial throat erosion of a 100 round barrel break in, I was a little longer than I wanted for the 220gr bullets. You'll get some decent growth initially, then it slows down once the lands is worn in. My current reamer has .225". So now once the barrel is broke in and has sped up for serious load development, I'm sitting right where I want to be for free bore on the 220s.

What kind of barrel life you getting?

 

[otnot]

Hornady might have a set also.
View attachment 1479844

When did Hornady start producing these dies?

 

[Alex Wheeler]

Theres so many bullet options you can end up from .200 to .300 depending.

 

[284winner]

A good friend has a 300 NM and really likes it. He's curious about improving the chamber. He asked me if I thought it would improve performance enough to make it work doing. Of course my response was yes but I enjoy the improved case for other reasons besides just performance. Based on the numbers I'm seeing with you guys and the improved 35°, it certainly looks impressive. I guess I sort of look at the 300NM like I do my 338 LM imp 40°. Comparing it to the standard 338 LM 20° with less taper to mine with a blown out shoulder, it's a no brainer. I love the improved version of almost all cartridges

 

[schw15]

I been using .275 kind of long to take 250 s and 230 s exclusively

Your saying that the .275 is to long for the 250 and 230 a-tip? I know Alex told me .235 for 220 bergers I think it would work ok for the 250 a-tip

 

[Sgt. Brumbaugh]

If chambered specifically for the 245 Berger (BT of course in front of N/S junction) recommended free-bore?
I am looking to mag feed these as well; OAL with the BT in front of the N/S junction?
8 or 9 twist for ELR 2500-2900 yards?

Thanks in advance.

 

[Tekardi]

Your saying that the .275 is to long for the 250 and 230 a-tip? I know Alex told me .235 for 220 bergers I think it would work ok for the 250 a-tip

I have 275 and works flawless with 250s , but will migrate to 245s as I m seing some problems with them in hot weather at 2900 fps, also the other fact is that I have 1-8 and a 30 inch tube, I would recomend 1-9 and 30 inch or longer for ELR ,

By the way we won last match of Grand Slam Argentina this rifle is a lazer, we won 3 of 3 Stages and General

Cadex Kraken Rifle plus Chasis Extension
Chambered 300 Norma Improved 35 AW
Bartlein 1-8 (1.35 to 0.90 ) 30 Inch
R50 90 grn Hornady s A Tip 250 @2890 ( 10 feet spread)
Lapua Brass
CCI Primers Large Magnum
Timney Hit trigger
Pierce Muzzle Break
Vortex Razor II
Solver Patagonia Ballistic

Thanks again Mr Wheeler for the reamer print !

 

[schw15]

I have 275 and works flawless with 250s , but will migrate to 245s as I m seing some problems with them in hot weather at 2900 fps, also the other fact is that I have 1-8 and a 30 inch tube, I would recomend 1-9 and 30 inch or longer for ELR ,

By the way we won last match of Grand Slam Argentina this rifle is a lazer, we won 3 of 3 Stages and General

Cadex Kraken Rifle plus Chasis Extension
Chambered 300 Norma Improved 35 AW
Bartlein 1-8 (1.35 to 0.90 ) 30 Inch
R50 90 grn Hornady s A Tip 250 @2890 ( 10 feet spread)
Lapua Brass
CCI Primers Large Magnum
Timney Hit trigger
Pierce Muzzle Break
Vortex Razor II
Solver Patagonia Ballistic

Thanks again Mr Wheeler for the reamer print !

Are you seeing the famous hornady bullets poof?

 

[Tekardi]

Are you seeing the famous hornady bullets poof?

Not only seeing, listening at certain distance a weird noise that is not normal like a squish or different sound ....just telling I preffer to switch to 245 s or maybe 230 solids