To ream or not to ream: .45 Colt Bisley throats

[eldon519]

I recently bought a 5.5" Bisley in .45 Colt. I own a reamer and pilots, so I checked the throats and 5 would barely pass a .4510 pilot with the 6th passing it more easily. I figured I'd shoot it before doing anything to it. Turns out it shoots like a laser compared to my 7.5" .45 Bisley, and has no leading with max H110 255gr cast SWCs. Can't say the same for my 7.5".

All was right with the world until I started playing with some longer 300gr bullets and found that they will not chamber entirely. Odd because I have some 355s that did. Anyway, I would like to be able to shoot most commonly available cast bullets, but I don't want to mess with this exceptional accuracy and lack of leading. My reamed 7.5" leads towards the muzzle and is not as accurate.

To the point, is there any chance reaming to .4525" from .4510" could make the gun less accurate or cause leading? I know usually the reverse is true, but don't wanna ruin a good thing on a hunch.

 

[yugorpk]

I ream ALL my Rugers right out of the box to .4525". Not one of them has complained.

 

[CraigC]

I'm always VERY leery of modifying an established good shooter. When I sent my 4 5/8" Bisley Super to David Clements I gave strict instructions not to do anything to effect accuracy, as it was already giving me 2"@50yds.

In your case, I'd probably ream it.

 

[Bartojc]

Pardon my ignorance, but it have to ask. I recently purchased a similar Blackhawks as the OP. Ruger Blackhawk Bisley 5.5 Stainless in 45 Colt. Only had it out a few times. I plan to reload for it. I do not cast my own, so I may or may not use lead right away, but likely will at some point use lead. Other than accuracy why would you ream the cylinders ? Will it always improve the accuracy or could you go the wrong way ? It seems it is common to ream the throats of the Blackhawk 45 Colts.

Thanks,

Jeff


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[LOLBELL]

Pardon my ignorance, but it have to ask. I recently purchased a similar Blackhawks as the OP. Ruger Blackhawk Bisley 5.5 Stainless in 45 Colt. Only had it out a few times. I plan to reload for it. I do not cast my own, so I may or may not use lead right away, but likely will at some point use lead. Other than accuracy why would you ream the cylinders ? Will it always improve the accuracy or could you go the wrong way ? It seems it is common to ream the throats of the Blackhawk 45 Colts.

Thanks,

Jeff


Sent from my iPad using Tapatalk

Reaming throats is usually not done for accuracy. I said "usually". It is usually done for bullet fit to shoot lead bullets. Throat diameter needs to be about .0015 larger that barrel groove diameter to shoot a bullet .001 larger than groove diameter to prevent leading. Of course accuracy is better without leading.

Several years ago Ruger had a bad reputation for having throats all over the place in 45 colts. I've seen them from .450 to .454 Even saw one cylinder with various sized throats from .451 to .453. How do you size a lead bullet for that revolver! Other calibers seemed to be much better on throat to groove diameter. You still here a lot of folks claim if you have a Ruger 45c you'll have to have the throats reamed.

Ruger has gotten their act together on the 45c's now I believe. I have 4, a Vaquero, a New Vaquero, a Blackhawk and a Super BlackHawk Hunter. All but the Vaquero came here with .4525 throats and a .451 groove diameter. they shoot my home cast just fine. The Vaquero is an older revolver and had to have the throats reamed to .4525 to handle lead without severe leading

 

[BSA1]

I use .454" cast bullets exclusively.

General advice is to use lead bullets .001 - .002" oversize.

 

[eldon519]

Well I reamed it and shot it today. Still shoots great and now will chamber the longer .452 bullets. Thanks for the feedback.

 

[Vern Humphrey]

Your problem is bullet profile, not throating. The 355s chamber because the nose portion is small enough to intrude into the throat without interference.

I say, if it ain't broke, don't fix it -- look for a 300 grain bullet with a different profile.

 

[ArchAngelCD]

eldon519, you mentioned your 5.5" revolver doesn't lead but your 7.5" does near the muzzle. When leading happens near the muzzle the most common cause is the bullet running out of lube. Try adding lube to the bullet and see if that helps.