oal expereinced help needed

[zx10mike 137]

they say there is no such thing as a dumb question so here goes.with regard o.a.l. my rifle prefers 2.249" i seem to use that oal on every recipie.this is very close to factory spec on the .204 and most people say seat the bullet out and lesson the jump the chamber is to long for me to reach the lands.my rifle seems to prefer slower loads = best group.so my question is this if i use more powder (faster bullet)should i try seating the bullet further out to keep the gap the same between the powder and bullet base.if i try faster loads with the bullet seated at 2.249" my groups begin to open.or is the o.a.l just the length your chamber prefers .thought i would ask as it saves me loading and firing yet anouther batch of test loads.if anyone can e enlighten me then thank you.

[dicehorn 38]

they say there is no such thing as a dumb question so here goes.with regard o.a.l. my rifle prefers 2.249" i seem to use that oal on every recipie.this is very close to factory spec on the .204 and most people say seat the bullet out and lesson the jump the chamber is to long for me to reach the lands.my rifle seems to prefer slower loads = best group.so my question is this if i use more powder (faster bullet)should i try seating the bullet further out to keep the gap the same between the powder and bullet base.if i try faster loads with the bullet seated at 2.249" my groups begin to open.or is the o.a.l just the length your chamber prefers .thought i would ask as it saves me loading and firing yet anouther batch of test loads.if anyone can e enlighten me then thank you.

 

Hi Mike

 

I will just jump in with two big feet !! I think what you actually mean (if you are referring to 204) is not AOL but COL. AOL is the measurement from the headstamp to the bullet's shoulder (Just before it tapers to the bullet tip) commonly called the ogive. Whereas COL is the neasurement from the headstamp to the tip of the bullet.

 

Yes it seems every reloader is hell bent on getting their bullets as long as possible to be 5 or 10 thou off the lands believing that is the way to get your bullets to fly accurately - that may well be true with barrels that are custom made with tight chambers, but for the rest of us with factory rifles it is not always the case. Consider this - many makes of factory rifles will not allow you to get within 40 thou of the lands bfore the bullet falls out of the case, also if it does stay in the case you can have problems in getting the loaded round to fit in the magazine. Lets face it, the reason is that most factory rifles like a jump into the lands.

 

The problem is that most reloaders have it in their heads that if the bullet is not within 40 thou of the lands it wont shoot well. What they usually overlook is what is going on in their case chambers - bullet seated long (near the lands) creates more air space in the case which means that when you fire the rifle (usually on the horizontal) the powder lies flat and because of this unwanted airspace you will get uneven burn. Now if you seat the bullet deeper - naturally you fill up this unwanted air space to create an even burn.

 

I shoot a factory rifle - how far from the lands am I? 222 thou back in a 22.250 and 180 thou back in my 6.5 - do my rifles shoot well?

 

http://i438.photobucket.com/albums/qq101/wyndog/100yardR9322250.jpg

 

Perhaps some of the 5 to 40 thou reloaders would like to tell me where I am going wrong.

 

In answer to your question - no you can answer it ! Would you prefer to be a speed freak with an extra 200 fps or an accuracy freak and see bullets touch.

 

If you decide to become an accuracy freak it does become a painful route. You will find that powder weight and distance from the lands are only two small steps towards your goal of accurate shooting. You will eventually learn that other factors are equally important - case weight, neck tension, the amount of the neck to resize. Its all about making your cases identical clones of each other. Oh and a phobia of cleaning the bore will help also. I reload for (I think) 8 people covering 11 calibres, the hardest calibre I reload for is a 17 Rem that groups about .3 it is capable of .1 but I cant get the owner to change to N133 powder ( he likes Varget)!

 

Lot of waffle but amongst all of it something may help you !!

 

Peter

[zx10mike 137]

wow tight group!thankyou for your help.i am neck triming and case sizeing, the best groups i get are .29" at 100 yards and like you say im an accuracy freak.becouse the 204 is a small bullet .29" can still have paper between holes and your one hole group is what i am chasing.i had a border 1 in 11 barrel fitted and i have been untill now full length sizing,just waiting for a redding neck sizer to be delivered.just do not want to leave any stone unturned.i assumed the guys getting better fps were still getting good accuracy.or what is the point? thanks for your help

cheers mike.

 

thanks for setting me straight on the col thing like a prune i thought oal ment over all length.

Edited April 8, 2011 by zx10mike

[jamie g 17]

if its really accurate I would worry about ringing some extra speed out of it. well some fast calibre rifles can run big speeds like the 204,22/250 220 swift

there best accuracy isn't always at the top end of the speed

[dicehorn 38]

wow tight group!thankyou for your help.i am neck triming and case sizeing, the best groups i get are .29" at 100 yards and like you say im an accuracy freak.becouse the 204 is a small bullet .29" can still have paper between holes and your one hole group is what i am chasing.i had a border 1 in 11 barrel fitted and i have been untill now full length sizing,just waiting for a redding neck sizer to be delivered.just do not want to leave any stone unturned.i assumed the guys getting better fps were still getting good accuracy.or what is the point? thanks for your help

cheers mike.

 

thanks for setting me straight on the col thing like a prune i thought oal ment over all length.

 

Taking your last sentence first OAL does actually mean over-all length - so I am not surprised it will confuse the beginner. I am afraid we can thank our friends across the pond for this. By overall, I believe they meant the part of the cartidge that would be in contact with the chamber (the tip back to the shoulder (ogive) of the bullet would not be in contact). If they had asked me to think of initials instead of OAL I would have come up with something like OM - Ogive Measurement - simples!

 

I see you have a border barrel with 1 : 11 that should shoot the 39/40 gr heads pretty well - and yes with that barrel, will permit you to seat heads pretty close to the lands. Assume you have had it pillar bedded? I have two friends with 204 (one with a border barrel) that shoot very well on an ogive reading of 1.905" using 39 gr Blitzkings, Both get around the 3800 fps but more importantly their spread is less than 15 fps.

 

It is not the end of the world to full length only (especially as you can achieve >.3") The only down sides are that your life expectancy with the brass will be reduced with the die moving back the shape of the brass body each time to SAAMI spec when in reality this expanded case is where you want it to be - fitting the case body to the dimensions of your chamber.

 

I use Redding dies both S type and competition ones (using bushings to vary the neck tension on the case) If you are not going for those but the ordinary straightforward neck die, once you have had a play about with it and seen how your groups perform, have a tweak with how much of the neck you re size. If you follow the instructions setting up the die in the press you will size just about all of the neck - this may give superb results on paper, however if not, try winding the die up out of the press say 3/4 of a turn to size less of the neck - it could make a difference - with small calibres, these minor adjustments can make all the difference.

 

I will soon have to go through all of the above - am having a 20 Tactical made in a Lothar Walther barrel 1 : 10 expected around June and have plans for it shooting out to 500 yds sub 3" (I hope!!)on our black feathered friends.

 

One final thing, you saw that group in my post above - hopefully you will also have noticed that I had drawn lines on the paper. You would be surprised at how many people tilt the rifle when taking a shot and don't realize they do and then perhaps on the next shot keep it straight then tilt again (I do!) this, when trying for tight groups will cause point of impact (POI) to change left/right. By drawing lines on the paper and matching your crosshairs to these lines when centering on the bull this will ensure consistency of the shooting position.

 

If I can help with anything with your 204 pm me - I know the above waffle must bore the pants off some people!!

 

Peter