headspace problem!! need help!!

[devildogandboy]

installed new to me 243ai barrel and used the ptg go guage, got everything snugged up and tried a fired full length sized piece of brass in it and can't get it to close. i checked thte dimensions of the brass and all seemed to be good. when brass is checked with the headspace guage i get 1.746, case length is 2.038.
also i could not get the correct dimensiions using the specified guage according to the hornady chart as they do not list the 243 ai, they show the "d" bushing to use for 243win but i went to the "a" bushing to get the correct dimensions. don't know if this is correct or not either.
if i haven't confused everyone so far, i want to know what to do so i can fire this thing to see how it shoots. thanks for the help.

[Blue Avenger]

are you using AI guages? ;)

[JackinSD]

A 2nd thought is, since it is a new to you 242ai, you might want to double check that also.

[devildogandboy]

are you using AI guages? ;)

yes, PTG 243 AI guage (go).

[devildogandboy]

A 2nd thought is, since it is a new to you 242ai, you might want to double check that also.

stamped on end of muzzle 243 win ackley.

[devildogandboy]

i might also add it is ER Shaw barrel, don't know if that makes anny difference.

[davemuzz]

From the measurements that I see about the .243AI on http://www.6mmbr.com/cartridgediagrams.html#243AI (Click the .243AI cartridge to get to the diagram) the Datum line measurement is 1.758, where you state it's 1.746 (no big deal) and you also state the case length is 2.038, where the diagram shows it to be 2.045. Again.....no big deal. Are you certain your measuring the distances at the right points?

Also....are you sure your F\L dies are adjusted properly so that they are "bumping" the shoulder down during the sizing?

Dave

[devildogandboy]

dave, hornady's chart for headspace guage says to use the "d" bushing to measure the 243 WIN. i tried this but the numbers were off dramatically, so i went and tried the "a" bushing and got the numbers where they should be. hornady does not show what headspace bushing to use for the 243AI. i don't know if this is right or wrong but i thought it might be the right bushing since i got all the right figures. this should give me the dimension at the datum line.

i have the redding deluxe die set for 243 win imp 40*, i have them cranked all the way down as far as they will go and some.
the fired brass i have came from someone on one of the forums i am on and i resized just to make sure they were gtg and the dimensions were the same as when i received the brass. the donor of the brass said they were sized and deprimed and i checked the dimensions when i got them and after i resized them and they didn't change. but they are good!
can't possibly bump the shoulder down any more, the dies are set as low as they will go.
and i did use the full length sizing die with a #3 rcbs shell holder and also tried with the #2 lee shell holder just in case there was any difference. there was none.

[geargrinder]

Take the barrel back off and check how much a sized case sticks out of the chamber. Compare it to you go gauge. I forget the proper spec. but it only needs enough sticking out for the case head to bottom out on the bolt face plus a few thou for clearance.

Hopefully, comparing the two protrusions will give you a better feel for which is correct.

If the brass fits fine, just set the barrel with your sized brass and some tape. Forget the gauge.

[devildogandboy]

geargrinder, depth of the bolthead is .118.
protrusion on the Go guage is .129 and the protrusion on the fully sized case is .140.
what do you think?

[drybean]

geargrinder, depth of the bolthead is .118.
protrusion on the Go guage is .129 and the protrusion on the fully sized case is .140.
what do you think?

just for poops @ gigles trim your case neck back

[dwm]

My full length die would not size a case enough to fit in a minimum chambered 260AI. Had to have the die turned down shorter ...

[devildogandboy]

just for poops @ gigles trim your case neck back

drybean, cut one case back .100 to 1.945 to use chamber length guage and without using the insert, it still would not close.
need more suggestions! help.

[devildogandboy]

could chamber be cut to short? i am new at this stuff but have been reloading for hunting many years.
still need help.

thanks for all the replies so far, i appreciate all the help!

[stangfish]

dave, hornady's chart for headspace guage says to use the "d" bushing to measure the 243 WIN. i tried this but the numbers were off dramatically, so i went and tried the "a" bushing and got the numbers where they should be. hornady does not show what headspace bushing to use for the 243AI. i don't know if this is right or wrong but i thought it might be the right bushing since i got all the right figures. this should give me the dimension at the datum line.


Hmmm. You manipulated your measurment to get good numbers but it didn't work. OK so using the D bushing check your PTG cauge. Now adjust your die to where the shoulder is at or near that same dimension using the D bushing on your brass. (If the gauge fits you must aquit) Lets headspace the barrel to fit the go gauge then lets size the brass headspace to fit the chamber.

Get back with us and tell us how it shoots.

[762frmafr]

geargrinder, depth of the bolthead is .118.
protrusion on the Go guage is .129 and the protrusion on the fully sized case is .140.
what do you think?

The go-gauge should stick out of the barrel the depth of the boltface plus approximatel 10 thousandths. Your brass is not sized correctly.

[devildogandboy]

stangfish, i have set my barrel useing the Go guage and snugged everything up, i have my dies cranked as far down as they will go and the brass is still too long to fit the chamber, this set-up will not allow me to close the bolt.
should i just set the barrel to the resized brass i got from someone else that i have fully resized and try shooting it with that set-up?

[devildogandboy]

My full length die would not size a case enough to fit in a minimum chambered 260AI. Had to have the die turned down shorter ...

i have the full length size die turned down as far as it will go, but the dimensions are fine! everything llooks good, just can't close bolt.
if i set barrel to resized case, everything works fine but i worry about the case hanging to far out of the chamber.

[JackinSD]

Do you have the top scope mount screws in place? I have seen where they are a bit too long and do not allow a bolt to close on a round.

[devildogandboy]

The go-gauge should stick out of the barrel the depth of the boltface plus approximatel 10 thousandths. Your brass is not sized correctly.

the headspace to the datum line should be 1.746 and that is what i have. dies will not turn down any further to bump or shorten this dimensiion. the Go guage protrusion from the barrel is .129 and if you add .010 =.139
my case is still .011 longer than that figure.