Throat wear issue.

[strut64]

I have measured about 25 to 30 mils wear on my Shilen st stl 6 Br after about 800 to 850 rounds. I am shooting 105 class bullets using Varget and RL15. My questions are; is this in line with others in terms of wear? Do you compensate for wear by seating the bullet out closer to the lands. In the case of 107 SMK bullets I started with optimum jump of about 20 mils. Accuracy is now only mediocre so I am assuming I have to shift the seating depth.`Is it direct or so you have to retest for optimum jump. Thanks in advance for your input

 

[4xforfun]

Define "mils" for me please.

 

[MGYSGT]

Don't know what a mil (maybe a millimeter) is, but just keep seating farther out as the barrel erodes until it's time to re-chamber or buy a new barrel.

 

[strut64]

1mil = 0.001 inch

 

[AckleymanII]

Funny how the term "mil" applies, I obviously missed the boat somewhere, also.

Yes, you have to chase the lands, normal procedure. Also, best to check at intervals and keep good records of such, as leade growth become predictable.

Depending on the caliber, measure every 100 or 200 rounds...what ever floats your boat. On my 7 STW, I measure every 50 rounds for giggles and grins.

 

[Alex Wheeler]

I have measured about 25 to 30 mils wear on my Shilen st stl 6 Br after about 800 to 850 rounds. I am shooting 105 class bullets using Varget and RL15. My questions are; is this in line with others in terms of wear? Do you compensate for wear by seating the bullet out closer to the lands. In the case of 107 SMK bullets I started with optimum jump of about 20 mils. Accuracy is now only mediocre so I am assuming I have to shift the seating depth.`Is it direct or so you have to retest for optimum jump. Thanks in advance for your input

Thats seems a little faster than normal, but different barrels will wear differently. I wounldnt worry about it. Let the gun tell you if the throat needs to be chased and how much.

 

[dmoran]

Mil is a thickness measurement unit is it not? (never seen it used for a length/distance measurement)

What measuring tool do you use that measures in Mil as length?
Donovan

 

[chapstix97]

I've seen mil used in thickness of garbage bags

 

[spclark]

That seems excessive compared to what I see in my 6's.

6HAGAR spacegun (1:7.5 Kreiger, ~ same case capacity as 6BR & 105 grain Bergers) wears about 0.005" in 400 - 500 rounds. My 6XC's (Bartlein, Brux; ~ 20% more propellant, same bullets) see about the same but those don't see strings of rapid fire.

RL15's not particularly noted for accellerated throat wear either. I use it in 6HAGAR for my 600 yard loads where 8208XBR or N140 gets used for 200-300.

 

[Ggmac]

Many variables when it comes to throat erosion . How fast you shoot , how long tour string , what leade angle was cut , barrel composition and how rifled and finally powder and primer . I'm sur I missed a few , but you get the idea .

 

[r bose]

My first leap into a high octane "6" is my 6xc. After 1425 rounds it has 155 thousands of throat erosion. I shoot 105's and now 115 DTACS. Having just shot a 1000 yd prone match the past weekend, it still shoots great and I'm gonna chase the throat till it either stops shooting or the 115's fall out of the stoney point gauge before contacting the lands. In any case I'm not expecting anymore than 1800 or so rounds total till I re barrel. But I knew that going in.

 

[PriMeR 260]

I just measured my savage 260 barrel and after 900 rounds and h4350 it is 21 thou farther out. Im not sure if thats good or bad being my first 260.

 

[6MMsteve]

I never miss a mil, lol

 

[Dusty Stevens]

Every time im aligning a pump or turbine somebody always brings up a mil but the dial indicators read in thousandths. I just tell em we're gonna go by thousandths since thats what indicators they sent and that seems to settle em out.

 

[waldo1979]

i assume the optimal jump/jam should remain consistent regardless of erosion. If it's a problem you can have the chamber re-milled. (you see what i did there)

 

[Dusty Stevens]

I seen it

 

[Webster]

I have measured about 25 to 30 mils wear on my Shilen st stl 6 Br after about 800 to 850 rounds. I am shooting 105 class bullets using Varget and RL15. My questions are; is this in line with others in terms of wear? Do you compensate for wear by seating the bullet out closer to the lands. In the case of 107 SMK bullets I started with optimum jump of about 20 mils. Accuracy is now only mediocre so I am assuming I have to shift the seating depth.`Is it direct or so you have to retest for optimum jump. Thanks in advance for your input

Why don't you try he simple approach. Seat 5 0.005" , 0.010" and 0.015" longer and see if it improves.