300 norma imp, is it worth it?

[Precision Underground]

I'm about to chamber up a 300 norma and want all the velocity I can get. Is it worth it to go imp to get more speed? How much extra cost are we talking? I guess I would need to buy a reamer and custom dies. I don't care about being able to shoot factory ammo at all. Pros/Cons? Anyone who has gone imp, would you do the same over again? What kind of velocity and pressure are you getting with the imp vs standard? @bjay I know you have done a lot of this. Thanks in advance.

 

[JMcBurn]

I'm about to chamber up a 300 norma and want all the velocity I can get. Is it worth it to go imp to get more speed? How much extra cost are we talking? I guess I would need to buy a reamer and custom dies. I don't care about being able to shoot factory ammo at all. Pros/Cons? Anyone who has gone imp, would you do the same over again? What kind of velocity and pressure are you getting with the imp vs standard? @bjay I know you have done a lot of this. Thanks in advance.

Might want to have your smith cut you a fireforming barrel so you don't burn 10% of the barrel out fireforming brass.

 

[Precision Underground]

Might want to have your smith cut you a fireforming barrel so you don't burn 10% of the barrel out fireforming brass.

That was def a concern. But I'd be willing to sacrifice some barrel life to gain 150 fps if that was the trade off. But would the extra 150 fps make the life even shorter on top of having to fire form?

 

[260shooter]

Yes it will. As they say. Speed cost. I would say unless you will be consistently shooting over a mile, the juice isn't worth the squeeze. Barrel life is somewhere around 900-1000 on a straight 300 NM.

 

[bjay]

I'm about to chamber up a 300 norma and want all the velocity I can get. Is it worth it to go imp to get more speed? How much extra cost are we talking? I guess I would need to buy a reamer and custom dies. I don't care about being able to shoot factory ammo at all. Pros/Cons? Anyone who has gone imp, would you do the same over again? What kind of velocity and pressure are you getting with the imp vs standard? @bjay I know you have done a lot of this. Thanks in advance.

Not much velocity to gain..a .2-.3 mil at thousand yards diff is much smaller than shooters error from reading the wind..gaining fps probably my last reason why i improved them.ive done 35 30 and 33 degree...not trimming often becoz brass not stretching as quick help you save brass life..
I just like the look of it
Also fireforming while breaking in barrel is fun..this cartridge can only give 14-1700 rds anyway a quality lapua brass (im using necked down 423 dakota) 100pieces lasted me almost 20x loading..thata more than enough for one barrel life..you wanna see noticeable gain in fps then do ackley improved..also you can fireform brass doing cream wheat method if you dnt wanna burn some barrel life..my fireforming load is accurate i shoot it to one mile

 

[Precision Underground]

Not much velocity to gain..a .2-.3 mil at thousand yards diff is much smaller than shooters error from reading the wind..gaining fps probably my last reason why i improved them.ive done 35 30 and 33 degree...not trimming often becoz brass not stretching as quick help you save brass life..
I just like the look of it
Also fireforming while breaking in barrel is fun..this cartridge can only give 14-1700 rds anyway a quality lapua brass (im using necked down 423 dakota) 100pieces lasted me almost 20x loading..thata more than enough for one barrel life..you wanna see noticeable gain in fps then do ackley improved..also you can fireform brass doing cream wheat method if you dnt wanna burn some barrel life..my fireforming load is accurate i shoot it to one mile

Pros and cons on the AI?

 

[Precision Underground]

Yes it will. As they say. Speed cost. I would say unless you will be consistently shooting over a mile, the juice isn't worth the squeeze. Barrel life is somewhere around 900-1000 on a straight 300 NM.

That’s exactly what I’m wondering is if the juice is worth it. I’d say main use will be between 1000 and one mile, with some just for fun shots out to 2000+. Unless conditions are just right we can’t even see hits on the 1 mile plus targets so it may not be worth it.

 

[DAVETOOLEY]

I've wildcated many cartridges over the years. Many of which I've made dies for. I have done a 300 Lapua Imp. 30 degree shoulder. I settled on 30 because they worked better in FL dies. On the 40 degree, large diameter cartridges it seemed like I was compressing the side walls not massaging the case body. That led to case separation issues if you weren't careful. Are wildcats worth the price. Probably not. I've pretty much done it all. Pre RUM I did the 404 Jefferys case in 7,30 and 338. The 8X68S case in 25,7,30 and 338. All of the standard Ackley's . With the bullets we have now taking a poke at a mile is pretty easy. Big bullet @ 2900-3000 FPS will easily get the job done. As I get older I find I can do more with less.

 

[Precision Underground]

I've wildcated many cartridges over the years. Many of which I've made dies for. I have done a 300 Lapua Imp. 30 degree shoulder. I settled on 30 because they worked better in FL dies. On the 40 degree, large diameter cartridges it seemed like I was compressing the side walls not massaging the case body. That led to case separation issues if you weren't careful. Are wildcats worth the price. Probably not. I've pretty much done it all. Pre RUM I did the 404 Jefferys case in 7,30 and 338. The 8X68S case in 25,7,30 and 338. All of the standard Ackley's . With the bullets we have now taking a poke at a mile is pretty easy. Big bullet @ 2900-3000 FPS will easily get the job done. As I get older I find I can do more with less.

Any tips on brass care with the standard 300 shoulder?

 

[DAVETOOLEY]

Any tips on brass care with the standard 300 shoulder?

Just a set of dies that match the chamber dimensions. Sizing even this large case shouldn't be a workout if everything is right.

 

[bjay]

I've wildcated many cartridges over the years. Many of which I've made dies for. I have done a 300 Lapua Imp. 30 degree shoulder. I settled on 30 because they worked better in FL dies. On the 40 degree, large diameter cartridges it seemed like I was compressing the side walls not massaging the case body. That led to case separation issues if you weren't careful. Are wildcats worth the price. Probably not. I've pretty much done it all. Pre RUM I did the 404 Jefferys case in 7,30 and 338. The 8X68S case in 25,7,30 and 338. All of the standard Ackley's . With the bullets we have now taking a poke at a mile is pretty easy. Big bullet @ 2900-3000 FPS will easily get the job done. As I get older I find I can do more with less.

Dave I just received my reamer from JGS (pinoykillaz at accurateshooter.com)
Thnx for helping me out and for your suggestion freebore diameter to .3092 and not doing more than 35°
I think our 33° is going to be perfect
And for the OP, if you dont like fireforming and planning to shoot factory ammo.i wouldn't do improved..even a standard 300nm with 28" can give you 3-3100 fps with 230s if thats your fps goal..thats is more than enough fps even to 2k yards

 

[Precision Underground]

Dave I just received my reamer from JGS (pinoykillaz at accurateshooter.com)
Thnx for helping me out and for your suggestion freebore diameter to .3092 and not doing more than 35°
I think our 33° is going to be perfect
And for the OP, if you dont like fireforming and planning to shoot factory ammo.i wouldn't do improved..even a standard 300nm with 28" can give you 3-3100 fps with 230s if thats your fps goal..thats is more than enough fps even to 2k yards

Thanks for the info fellas.

I’ll be shooting reloads only but would rather not have to fireform unless the upside was worth it. I’m not too worried about having to trim brass every few firings. If there isn’t much of a velocity increase I’m not sure it would be worth it to me.

 

[rts5577]

Dave Tooley...I’ve got a barrelnordered for a .300 NM IMP and the reamer is ordered. Not sure the dimensions of the reamer my Smith ordered but what I’m curious about is a gain twist barrel. I’ve read a little about gain twist in the caliber and from what little bit I’ve read, it worked out very well. Do you have any insight?

 

[kthomas]

Dave I just received my reamer from JGS (pinoykillaz at accurateshooter.com)
Thnx for helping me out and for your suggestion freebore diameter to .3092 and not doing more than 35°
I think our 33° is going to be perfect
And for the OP, if you dont like fireforming and planning to shoot factory ammo.i wouldn't do improved..even a standard 300nm with 28" can give you 3-3100 fps with 230s if thats your fps goal..thats is more than enough fps even to 2k yards

I hope that a 230 Berger traveling at 3-3,100 fps can make it to 2k - if not, someone needs to tell my lowly 140 grain 6.5 bullets traveling at 2780 fps that they are doing the impossible ?

In all seriousness, 3,000-3,100 for may be a stretch depending on your environmentals and the powder you are using. My .300NM shooting 230 Bergers pressures out at around ~2950 fps with a 29" pipe. This is with Retumbo, and at 7000 ft DA at 100°F. Should still get me out to 2500-3000 yards.

 

[bjay]

I hope that a 230 Berger traveling at 3-3,100 fps can make it to 2k - if not, someone needs to tell my lowly 140 grain 6.5 bullets traveling at 2780 fps that they are doing the impossible ?

In all seriousness, 3,000-3,100 for may be a stretch depending on your environmentals and the powder you are using. My .300NM shooting 230 Bergers pressures out at around ~2950 fps with a 29" pipe. This is with Retumbo, and at 7000 ft DA at 100°F. Should still get me out to 2500-3000 yards.

A 3-3100 230berger coming from 300nm would smoke creedmoor 2900 140gr at 1mile with the same shooter behind the trigger

 

[kthomas]

A 3-3100 230berger coming from 300nm would smoke creedmoor 2900 140gr at 1mile with the same shooter behind the trigger

Absolutely it would! No contest there, if it did, I wouldn't have a .300NM ?

 

[bjay]

Absolutely it would! No contest there, if it did, I wouldn't have a .300NM ?

Me shooting my 300nm at 2k yards vs franky and his 6.5 creed..no brainer! Never put your money on me lol