Looking for some advice and knowledge

johnnyrhea1969 · #1 03-18-2020, 04:52 PM

Hello good people ,,, have a question. I recently built an AR-10 in 6.5 CM. I'm experiencing an issue with the hand loads I'm using . My COAL Is right on par with load data for the bullets I'm using. BUT when I insert the Mag and send the bolt home ,, I pul the trigger and CLICK !. Nothing ... This is where it gets odd. I can eject the unfired round, MANUALLY load it , close the bolt, then re insert the Mag pull the trigger and BANG,,,, the whole mag will run without Issue. I can Load the mag with all factory loads and not have this issue,, so I'm thinking it's either shoulder or seating issues..... Anyone out there every have thins happen?

Ivan the Butcher · #2 03-18-2020, 06:01 PM

Forget the COAL from the bullet manufacture, All you need to worry about is, a)will it fit in the mag & b) is the crimp in the cannelure?

Next check your hand loaded round to a factory round. Check for a slight bulge at the shoulder. If so, very likely you have seated the bullet (and crimp) too deep. If that is the case take those reloads apart and full length size again and check for case length and trim if necessary. The seating plug probably needs backed off 1/4 turn OR the whole die needs backed off a 1/4 turn without adjusting the seating plug.

Ivan

scooter123 · #3 03-18-2020, 06:08 PM

I suspect that you are easing the bolt closed with the first round instead of pulling the bolt all the way back and just letting go. If so one obvious answer is to change your procedure.

However even if my guess is correct that tightness on closing indicates that either you have an overall length that is a bit too long or you need to bring the shoulders back by about 0.005 inch. Because your cases may have the shoulders set just a tiny bit past the maximum for your chamber. If you have a case gauge that can tell you if your cases are withing spec for the shoulder position. However if your chamber is just a touch "short" that case gage won't provide much guidance unless to tweak that case gage to match your rifle.

A very simple test can be used to allow to set up your sizing operation so that your cases will always fit your chamber. That is to take a freshly sized case, insert it into the bolt face so it's retained by the extractor and drop the bolt. Then take the changing handle and pull on it gently. If it comes free without and drag your shoulder position is not too long. If you have to really pull or even "mortor" the bolt free your shoulders are set too long. Drop the die down my something in the range of 1/12 of a turn and try again.

fredj338 · #4 03-19-2020, 12:32 AM

OAL is the most misunderstood portion of reloading, even for some exp reloaders. What is in the data ONLY works for that exact bullet in that exact barrel. Every barrel is diff. Every bullet type is diff. So you must match the bullet & oal to your barrel. Yes that may mean seating deeoer but in a rifle, not that big of an issue. What you do not want is a bullet jambed into rifling. As scooter notes, could be a sizing issue too. I had issues with my 1st ar loads not being sized far enough down with range pickups.

Ivan the Butcher · #5 03-19-2020, 08:05 AM

Quote:

Originally Posted by fredj338

As scooter nores, could be a sizing issue too. I had issues with my 1st ar loads not being sized far enough diwn with range pickups.

The loading dies available now days include the RCBS Black Box dies for AR's The Full Length sizer is also a Small Base sizer, and the Seating die is a Taper Crimp/Seating die. There is less fuss about case length with a T/C die for AR's. (as long as brass in not over max length!)

The opposite of a Small Base sizing die is a Neck Size die (usually a no-no for any Semi or Full Auto rifle.

Inside these extremes of sizing dies some companies just make one option, and sometimes they tell you what it is and sometimes they don't!. Redding, RCBS, and Wilson arbor dies (they don't thread into a press) also have a neck sizing collet system available, where you pick a finished neck outer diameter based on chamber dimensions and the exact neck wall thickness. (I have used this for semi-autos and it is a waste of extra money and time! IT IS A BENCH REST SYSTEM OF LOADING! But in that system is a die called a body die, which is a Full Length die that never touches the neck, allowing the removal of small bulges in already loaded ammo, and can be adjusted to bump the shoulder back 0 to 10 1000ths if you wish. Redding makes the best dies for this.)

Ivan

SMSgt · #6 03-19-2020, 10:25 AM

Sounds sort of like the issues I had with my 6mm Mongoose AR build. The Mongoose is a .223 wildcatted to 6mm.

I built an Aero Precision upper and mounted it on my Armalite lower and had nothing but clicks, stuck cases, and/or feeding issues. While I expected a few initial problems with a wildcat cartridge, this thing was a major problem.

Long story short, there must have been some tolerance stacking or something as when I built a new Aero Precision lower, it all ran fine.

I had some other problems such as establishing proper head spacing. Used a Hornady head space comparator to sort that out.

As far as COL goes, I rarely use exact published data. It's an approximation for most guns. I use a bullet and cleaning rod to establish maximum "touch-the-lands" COL for each bullet make/weight I reload in a rifle. Often that "allowable" COL will exceed the mag length for my AR, so COL can never exceed that.

fredj338 · #7 03-19-2020, 02:26 PM

Quote:

Originally Posted by Ivan the Butcher

The loading dies available now days include the RCBS Black Box dies for AR's The Full Length sizer is also a Small Base sizer, and the Seating die is a Taper Crimp/Seating die. There is less fuss about case length with a T/C die for AR's. (as long as brass in not over max length!)

The opposite of a Small Base sizing die is a Neck Size die (usually a no-no for any Semi or Full Auto rifle.

Inside these extremes of sizing dies some companies just make one option, and sometimes they tell you what it is and sometimes they don't!. Redding, RCBS, and Wilson arbor dies (they don't thread into a press) also have a neck sizing collet system available, where you pick a finished neck outer diameter based on chamber dimensions and the exact neck wall thickness. (I have used this for semi-autos and it is a waste of extra money and time! IT IS A BENCH REST SYSTEM OF LOADING! But in that system is a die called a body die, which is a Full Length die that never touches the neck, allowing the removal of small bulges in already loaded ammo, and can be adjusted to bump the shoulder back 0 to 10 1000ths if you wish. Redding makes the best dies for this.)

Ivan

Not much camming action in an AR. I use the RCBS 'X' FL SB dies & needed just another 0.002" sizing to get 100% reliable chambering. It required I set the die up for a slight cam over vs just touching the shell plate on my 550.

johnnyrhea1969 · #8 03-21-2020, 05:34 PM

Hey man thanks for the response.. So heres the deal .. I went out and got a Hornady COL Gauge, as well as the bullet comparator . I used a modified case and the COL gauge and the numbers I got were. 2,800 Case over all. then I used the comparator to do a base to Ogive which was 2,284. So with that all being said ,,, when I do my loads should I use the Base to Ogive measurment, and just back of ONE thou for my jump.. how do I know what is TOO MUCH jump ?

johnnyrhea1969 · #9 03-21-2020, 05:39 PM

Hey man thanks for the response.. So heres the deal .. I went out and got a Hornady COL Gauge, as well as the bullet comparator . I used a modified case and the COL gauge and the numbers I got were. 2,800 Case over all. then I used the comparator to do a base to Ogive which was 2,284. So with that all being said ,,, when I do my loads should I use the Base to Ogive measurment, and just back of ONE thou for my jump.. how do I know what is TOO MUCH jump ?