Does N570 really torch the throat quickly?

[Kimber7man]

Shooting some 300WM loads with a 215 Berger hybrid and N570. Don't know the charge, it is loaded ammo from Unknown Munitions.
Rumor has it that N570 is notorious for toasting throats quickly.
What has your experience been with N570? Will it burn the throat up quickly if I'm shooting 3-5 shots and then letting the barrel cool off?
Thanks!

 

[Mike D Texas]

Shooting some 300WM loads with a 215 Berger hybrid and N570. Don't know the charge, it is loaded ammo from Unknown Munitions.
Rumor has it that N570 is notorious for toasting throats quickly.
What has your experience been with N570? Will it burn the throat up quickly if I'm shooting 3-5 shots and then letting the barrel cool off?
Thanks!

Yes it burns very hot. I would wait at least 1 minute between shots, even on 3-5 shot strings.

 

[WeiserBucks]

Let it cool between shots unless it's an old barrel that you're in a hurry to replace.

 

[WapitiBob]

buy a chamber chiller

 

[VinceMule]

Letting it cool in between shots will help, I use 50/50 water and alcohol during the Summer months, apply with a washrag till the solution is dripping off the bottom of the barrel, cools barrels so quickly, you will not believe it.

The real answer to the question lies in how much heat a particular powder generates during ignition. There is a Heat Index chart of powders that ranks them in how hot they burn. This Heat Index chart is NOT the Relative burning rate chart.

The N500 series of powders are among the hottest burning powders on the market today. Shocking that Varget, IMR 8208, and H4895 are not too far behind.

I learned a very hard lesson with a 220 Swift shooting N550 hunting coyotes. With these very hot burning powders, they normally wipe out 9" of the barrel from the throat forward.

All of us have various amounts of disposable income on this hobby, so you can get a wide variety of answers.

 

[crashlanding]

The chart Vince may be referring to

 

[Taylorbok]

it's definitely harder on the throat than other powders.
That being said how much do you shoot? Most people don't shoot enough to ever really worry about burning a barrel out. On the otherhand some people shoot lots and can burn several barrels a year.

I'd say if you don't do long strings of fire, keep it to 5 or 6 at most and let the barrel cool well between groups you will get over 1500 rounds from the barrel.

 

[VinceMule]

Yes, that is it. N500 series have 20% DNT.

Again, the shot strings are not the big deal, the Heat generated upon ignition is the big deal. The barrel is going to be very hot on any five-shot group. I could measure .012-.020 leade growth on every 50 shots fired with my Swift.

1500 will be a stretch, to say the least. I got 800-900 using IMR 4831 in my two 6/284's. A one inch group is HUGE to me. I changed to AA2700 in the New Swift re barrel with 50-60g bullets with amazing accuracy and speed, one of the coolest buring powders made.

Take a look at the Heat Index chart, look how cool the N165 burns, I would start there.

 

[Kimber7man]

Thanks, I'm normally a 3 shot to 5 shot guy when at the range. Have about 150 of these rounds left, I'll take it easy with them and then switch to H1000...

 

[VinceMule]

Forget the 5 shot, those 4th and 5th shots cook the barrel! Good call on the H1000, N165 and N160 are both good choices also.

Best of luck!

 

[Phil Rizzo]

Wonder where N565 fits in the list? R26?
I'm going to assume they are located in the column on the right….and closer to the bottom.

 

[crashlanding]

Wonder where N565 fits in the list? R26?
I'm going to assume they are located in the column on the right….and closer to the bottom.

That's N530 and N540 bottom right. N565 and RL26 didn't make the list

 

[Taylorbok]

Wonder where N565 fits in the list? R26?
I'm going to assume they are located in the column on the right….and closer to the bottom.

N565 should land between 560 and 570, I'd imagine RL 26 be in the same zone

 

[Phil Rizzo]

N565 should land between 560 and 570, I'd imagine RL 26 be in the same zone

For burn temperatures?
I'm aware of the VV powder burn rates.