Now having COAL issues for .45 Colt.

[Idaho45guy]

My very first batch of reloads using the Hornady 250 gr XTP and 23.5grs of Lil' gun, I paid no attention to COAL; just ran the boolits down to the crimp band. Dumb.

Now I'm using some 300gr cast boolits with 17grs of Lil' Gun and the COAL listed from Hodgdon is 1.650 with 18.0 grs as starting. I did 17grs. But, the rounds won't full seat in my cylinder. They seat perfectly at 1.602.

How do I figure out how much I risk increasing pressure by seating the boolits in that much further? They are basically unusable at the stated length and I am going a full grain under minimum.

I'm thinking it should be fine, but I thought I better check here before touching them off.

Using the Titegroup data from Hodgdon, it is the same COAL of 1.650 but 7.5grs. It looks like for these 300gr boolits to work in my pistol, I need to seat them deeper than Hogdon has listed. Other load listings I see don't even give the COAL. But from what I've been able to gleen from here and other sources, it is vital to getting correct pressures...

My cylinder with reload at correct COAL on left, factory ammo in middle and deeper seated reload on right:

178322

[contender1]

This is one of the reasons we always start new loads on the low side & work up. If you do a little internet searching,,, you will see a lot of folks deep seat bullets,,, even over the front driving band in some cases. This allows the use of a heavier bullet in many guns.

[rancher1913]

as I found out recently after a lot of research, the COAL listed in the book is the maximum, you need to adjust to each gun. make sure you are not compressing the powder when you seat deeper and start on the lower end of the powder charge. the factory crimp dies will sometimes stretch the COAL so watch that. I droped the coal on my 9mm from 1.169 to 1.160 and all my problems went away with no signs of over pressure, but I did make absolutely sure I would not be compressing the powder before I reduced the COAL

[RobS]

Assuming the Hornady 300 grain xtp's are .452" diameter bullets I would think that more than likely your cylinder throats are tight or smaller than this. I would have your cylinder throats reamed if you have not already as Ruger 45 Colts are notorious for this. Pressures can rise more than expected (more than the reloading books) when trying to push a jacketed bullet through a tight cylinder throat. The Ruger Bisley I had came with .449 to .4505 throats. I personally reamed all throats to a uniform .4525" so I didn't have issues. Heck two cylinder throats were .449 in the Bisley and with a .450 barrel groove diameter shooting cast boolits was less than desirable.

[pmer]

+ one for tight throats. Try pushing a sized boolit in the throats, they should pass through fitting kinda snug.

[DougGuy]

You might need to send the cylinder and have the throats reamed to .4525" I do a lot of these and it fixes the issue straightforward. DO NOT seat these heavy for caliber boolits deeper, as this can raise pressures DANGEROUSLY.

The way to do this is to have the cylinder throats reamed and honed all to the same size, then load per the COA in the published load data. You are playing with a hand grenade by seating deeper and "guessing" how much to reduce powder charges. I do a couple hundred Ruger cylinders every year, Very good work done, lots of happy customers here on the forum. You can't even buy the reamer for what it costs to have it professionally done. Shoot me a PM for details.

I would not shoot those. I would pull those boolits and reassemble once your cylinder gets done. Slow burning powder generally needs a high load density to be safe, I am not sure how LilGun will react with a load density lower than 70% of the case volume below the boolit, but it is generally an industry accepted standard to avoid downloading W296/H110 below minimum published starting weight, it can be dangerous and unpredictable below 75% load density and is not recommended to download it.

I use 2400 and LilGun to get in the 75% ~ 90% power range of the Ruger single action, which is just below the starting weight of 20.5gr H110 with the 300gr RF boolit. I wanted to develop a slightly less than max hunting load in the 1150 ~ 1200fps velocity and H110 gave a little more than I wanted. LilGun worked great for this, but I did not go below their starting weight. I think the weight that gave me the best accuracy was 20.5gr.

[DougGuy]

Just for reference, here is a 500 S&W cylinder that was sent in for throat reaming, throats are a very tight .500" and the boolits, which sat on a shelf after being sized in a Lyman sizer with a .500" die, now mic at .5015" and it's very obvious that they won't go through the throats. With loads and cartridges that operate near maximum safe pressures, all this does is create a situation where the boolit must be swaged down by firing, to go through the cylinder throats, which can raise pressures dramatically depending on how hard the alloy is.

Cast boolits, depending on how much antimony is in the mix, tend to grow as they sit after casting, it's a part of the "age hardening" that they do. It's not unusual for a .44 or .45 caliber boolit to grow as much as .0003" to .0006" as it age hardens. This is why it is important to have throats sized .0005" to .001" greater than boolit diameter, so that for one, the assembled loads will still fit in the cylinder, but most importantly, so that an over pressure event will be avoided. Groups will ALWAYS be smaller with throats and boolits which are dimensionally correct.

http://i1202.photobucket.com/albums/bb374/DougGuy/Cylinder%20Services/DSC05131_zpsxxvmcvlu.jpg (http://s1202.photobucket.com/user/DougGuy/media/Cylinder%20Services/DSC05131_zpsxxvmcvlu.jpg.html)

It is my understanding that the longer the boolit is in comparison to it's diameter, the more the diameter will grow as the boolit sits. I believe that the age hardening actually compresses the boolit's length, which causes the diameter of the boolit to grow.

These boolits for the 500 S&W were sized to .500" after casting by the Lyman sizer. Between the known springback of the alloy, and sitting while age hardening, they have gained .0015" in diameter, which is a LOT. Cylinder throats have to be sized with the dimensionally changing properties of the alloy in mind for the boolit to have proper fitment in the throats.

For your 300gr RF boolits, which are also quite long in relation to their diameter, you might want to keep this in mind and take some measurements as they are sized then check them in a few months.

[Tackleberry41]

You will not like touching off those ones w 23gr of powder. I have several 45 colts. 1 is standard pressure, 2 are rifles, and a Ruger blackhawk. So have loaded a wide variety of ammo for the colt. I am using the 240gr XTP mag in my Rossi 92, went with the mags due to the velocity at 1720fps using W296, 22gr. I fired one out of my blackhawk, one, wont again. Was the loudest thing I have ever fired, and that was after 4 yrs in the marines. For all the muzzle blast the velocity was not there w the shorter barrel. I get the same velocity using Unique and way easier on the ears. Yes I was wearing muffs it was still way to loud.

Question on you OAL issues is, is it tight throats? Or just the cyl isnt long enough to get the book OAL? My blackhawk is a little tight, but not enough you cant get them to chamber. The Ruger only data and OAL is based on being loaded in a blackhawk, which has a longer cyl than a standard 45 colt. My blackhawk loads will not fit in my standard pressure gun due to length.

But yea the listed velocity and pressure is based on the OAL they list. You change that length, velocity and pressure changes. You can shorten them, but its hard to know without some way to measure like a chronograph. I have shortened stuff before, just adjusted the charge to go with it. 7.62x25 will not fit in a 38 super mag to go thru a 1911. My hot charge is the min listed in the book due to the length. But I can run them over a chrony, compare it to expected results from the book.

[Idaho45guy]

I checked the cylinder throats and they were definitely undersized; can't remember the numbers off the top of my head. Seems like they were around .450 or .449. one was just a hair smaller than the others. I have been unable to push any of my boolits through the cylinder with finger pressure. I checked the barrel and it was another two or three thousandths smaller than the cylinder, which I was told was all good and normal.

I've never had any gunsmithing done... What's a normal rate for something like reaming the cylinders? I know what a machine shop would charge for doing it to a V8 engine...

[dubber123]

I checked the cylinder throats and they were definitely undersized; can't remember the numbers off the top of my head. Seems like they were around .450 or .449. one was just a hair smaller than the others. I have been unable to push any of my boolits through the cylinder with finger pressure. I checked the barrel and it was another two or three thousandths smaller than the cylinder, which I was told was all good and normal.

I've never had any gunsmithing done... What's a normal rate for something like reaming the cylinders? I know what a machine shop would charge for doing it to a V8 engine...

It's pretty cheap to have Doug do it. .449 or .450" would be cause for me to lick a stamp and send that cylinder away pronto. I'd check for a constriction at the frame junction, that will give you a skewed bore measurement, and you will be much happier when that is addressed too. You might get lucky and have a proper barrel from the factory. I wouldn't count on it. :)

[RobS]

What I gather is your Ruger Bisley barrel's groove diameter is .002-.003 under those .449 to .450 cylinder throats. Not saying this isn't possible however I have never seen or heard of a Ruger 45 Colt Barrel being way under specification. We are talking about .446-.447 groove diameter.

[DougGuy]

That measurement sounds like someone measuring the barrel with calipers. For a good long while now Ruger .45 barrels have been right at .451" in the groove, which makes them .4425" ~ .443" in the lands. .450" is a typical measurement for a roll engraved unfluted cylinder for a bisley, in my experience those generally run the tightest of all Ruger .45 caliber cylinders.