Site seems to be OK. Load issue should be resolved now.
Side Gate 38-55 Groove Diameter?
Side Gate 38-55 Groove Diameter?
Been trying to find this...will email Henry if I have to, but thought I'd check here first.
Does anyone know the groove diameter of the 38-55 Henry?
Historically 38-55s have varied somewhat...from .375 to near .380. I had a 38-55 Marlin that was .377.
I am jonesing for a side gate and my mind is telling me do a 30-30, but my heart is saying do 38-55. Just want to know what I might be up against from a bullet availability standpoint.
Thanks in advance,
Tim
Does anyone know the groove diameter of the 38-55 Henry?
Historically 38-55s have varied somewhat...from .375 to near .380. I had a 38-55 Marlin that was .377.
I am jonesing for a side gate and my mind is telling me do a 30-30, but my heart is saying do 38-55. Just want to know what I might be up against from a bullet availability standpoint.
Thanks in advance,
Tim
USMC 1976 - 1980 0351
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
- JEBar
- Town Marshal / Deputy Admin
- Posts: 20447
- Joined: Sun Mar 20, 2016 10:58 pm
- Location: central NC

Re: Side Gate 38-55 Groove Diameter?
for such info, I believe you'd be wise to go directly to Henry or speak with someone who has .... their introduction of 38-55 caliber to their lineup is so new that we haven't had a great deal of info posted about them ..... my hunch is Henry will manufacture theirs to meet SAAMI specs .... please post what you learn
-
Old Syko
Re: Side Gate 38-55 Groove Diameter?
Mine measures .3765 but others are reporting .376 even. Only way to know is to slug the bore. As I've said before, Henry isn't going to put out guns with great variables in bore diameter as has been done over the last 100+ years. I've been running slugs sized to .379 and am impressed with the accuracy. Only 420 down the pipe so far. I received 1000 bullets from Missouri Bullet that are Hi-Tek coated and sized to .379 but haven't gotten a chance to start working with them yet.
It's your nickel so spend any way you like but I'm more than a little impressed with this 38-55.
It's your nickel so spend any way you like but I'm more than a little impressed with this 38-55.
-
Old Syko
Re: Side Gate 38-55 Groove Diameter?
Looking forward to some load workup with these later in the week.
You do not have the required permissions to view the files attached to this post.
Re: Side Gate 38-55 Groove Diameter?
.
In my area .38-55 factory ammo is hard to find and very, very expensive.
In my area .38-55 factory ammo is hard to find and very, very expensive.
UPDATES: OR passes 114, "one of strictest gun control measures in U.S." https://henryrifleforums.com/viewtopic. ... 34#p213234
Re: Side Gate 38-55 Groove Diameter?
Mine was a tight 376 and there is more than enough people casting bullets for the 38-55. One of my favorite calibers and always has been. I assuming you reload if you have had one before. Guy at Montana Bullet works has 38-55 bullets in all sizes and could make you what you want. Yes locally 38-55 is more expensive for factory rounds than 30-30. You might be able to save some buying online. But I know for me there isnt any doubt which one I would buy if my heart told me 38-55. Maybe just get one of each we need more Henrys to add the running total anyway.
Don't let the old man in
H001T .22LR
H001T .22LR MONUMENT VALLEY
H003T PUMP .22LR
BBS .41 MAG
SS .357
SIDE GATE 38-55
H001T .22LR
H001T .22LR MONUMENT VALLEY
H003T PUMP .22LR
BBS .41 MAG
SS .357
SIDE GATE 38-55
Re: Side Gate 38-55 Groove Diameter?
What's factory ammo? lol
USMC 1976 - 1980 0351
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Re: Side Gate 38-55 Groove Diameter?
That might just be the right answer!
30-30, 32 Spl, 38-55 and 45/70 would make for a great lever line-up!
USMC 1976 - 1980 0351
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Re: Side Gate 38-55 Groove Diameter?
Thanks for the feedback guys.
I will send Henry a note about this and will let you know.
Tim
I will send Henry a note about this and will let you know.
Tim
USMC 1976 - 1980 0351
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Re: Side Gate 38-55 Groove Diameter?
Something you likely should consider is to slug the barrel, then you'll know for your rifle.
Re: Side Gate 38-55 Groove Diameter?
Trying to find out before I buy, so i’ll know if molds and sizers will work.
Certainly, if I already owned the rifle I would just slug the barrel.
In other news: I sent a note to Henry last night and already received a reply!
Their spec calls for a .376 groove diameter.
Tim
USMC 1976 - 1980 0351
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
-
Old Syko
Re: Side Gate 38-55 Groove Diameter?
As with all forms of machine work there has to be an allowable variable of + or - a given amount since we don't live in a perfect world. As more parts are made, tooling wears and dulls which is why there are such allowable tolerances. My gun being one of the first released measuring .3765 was likely cut with newer tooling than later built guns. As tooling wears within the spec'ed tolerance the bores will become tighter which is why I would suspect that tolerance level is likely .3765 to .3755 or possibly even more. That half a thousandth one way or the other is going to mean nothing compared to the way things were done in the past.
Re: Side Gate 38-55 Groove Diameter?
I actually did ask for the spec limits...I was hoping to learn the min/max.Old Syko wrote: ↑Mon Jul 01, 2019 3:03 pmAs with all forms of machine work there has to be an allowable variable of + or - a given amount since we don't live in a perfect world. As more parts are made, tooling wears and dulls which is why there are such allowable tolerances. My gun being one of the first released measuring .3765 was likely cut with newer tooling than later built guns. As tooling wears within the spec'ed tolerance the bores will become tighter which is why I would suspect that tolerance level is likely .3765 to .3755 or possibly even more. That half a thousandth one way or the other is going to mean nothing compared to the way things were done in the past.
I was actually quite happy just to get an answer!
USMC 1976 - 1980 0351
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
Henry H010
Henry H010CC
Savage M99 308 (born in '57 like me!)
Browning M53 32-20
336 30-30
No 1 300 H&H
No 1 375 H&H
1895 30-40 Krag
Ruger American 308
Several Nasty Black Rifles
-
Old Syko
Re: Side Gate 38-55 Groove Diameter?
It would be interesting to know but I suspect that is considered proprietary information.tarbe wrote: ↑Mon Jul 01, 2019 3:14 pmI actually did ask for the spec limits...I was hoping to learn the min/max.Old Syko wrote: ↑Mon Jul 01, 2019 3:03 pmAs with all forms of machine work there has to be an allowable variable of + or - a given amount since we don't live in a perfect world. As more parts are made, tooling wears and dulls which is why there are such allowable tolerances. My gun being one of the first released measuring .3765 was likely cut with newer tooling than later built guns. As tooling wears within the spec'ed tolerance the bores will become tighter which is why I would suspect that tolerance level is likely .3765 to .3755 or possibly even more. That half a thousandth one way or the other is going to mean nothing compared to the way things were done in the past.
I was actually quite happy just to get an answer!
Re: Side Gate 38-55 Groove Diameter?
I haven't shot mine yet but for testing purposes I bought a box of the 200 grain 375 sierra bullets. Eventually I will get to try some out. I also have some 250 grain gas checks in the same diameter I want to give a try. I will be using Reloader 7 which has been my go to powder for the 38-55.
Don't let the old man in
H001T .22LR
H001T .22LR MONUMENT VALLEY
H003T PUMP .22LR
BBS .41 MAG
SS .357
SIDE GATE 38-55
H001T .22LR
H001T .22LR MONUMENT VALLEY
H003T PUMP .22LR
BBS .41 MAG
SS .357
SIDE GATE 38-55
-
Old Syko
Re: Side Gate 38-55 Groove Diameter?
I originally was able to get nearly 1000 rounds of HSM 240 cast loaded ammo and that is what I've shot so far. The gun is very happy with them. They are the short brass but still shoot well. I'll start with the proper length brass from Starline. I doubt mine will ever see anything but lead slugs which is why I'm starting with the MB slugs. I have 2 moulds and will bring them into play the first chance I get. As to powder my choice will be H4198 to start. In cases of this size and load density It has always served me well. In my 444 it is the one and only powder so I keep a significant supply. I'll be loading for 2 different loads as usual, one being for maximum reasonably velocity and the other for pure accuracy that is most always much lower velocity.BigAl52 wrote: ↑Mon Jul 01, 2019 6:12 pmI haven't shot mine yet but for testing purposes I bought a box of the 200 grain 375 sierra bullets. Eventually I will get to try some out. I also have some 250 grain gas checks in the same diameter I want to give a try. I will be using Reloader 7 which has been my go to powder for the 38-55.
BTW It'll be interesting to hear how those little JFPs work.
Re: Side Gate 38-55 Groove Diameter?
Ive not used any of the longer brass. I have a 336 Cowboy Marlin and I think at one time I tried it that gun and something didnt go right. Need to try some again. I do have a bunch of the shorter brass which has worked well. I used some 4198 in the past and have used it in a 444. But one day I had brain failure and sold the 444. Shouuld have kept it. When I get to load some of those 200 grainers I will make a report.
Don't let the old man in
H001T .22LR
H001T .22LR MONUMENT VALLEY
H003T PUMP .22LR
BBS .41 MAG
SS .357
SIDE GATE 38-55
H001T .22LR
H001T .22LR MONUMENT VALLEY
H003T PUMP .22LR
BBS .41 MAG
SS .357
SIDE GATE 38-55
-
Old Syko
Re: Side Gate 38-55 Groove Diameter?
I've not sold, traded or otherwise disposed of any gun since the early 90s and wish I had back most of what I let get away before then but back then I looked at them as a savings account I could enjoy for a time. So for nearly 30 years now the only things that have gotten away are some that I've passed on to the kids and grandkids. Makes me sick to think of some I let go.BigAl52 wrote: ↑Mon Jul 01, 2019 9:22 pmIve not used any of the longer brass. I have a 336 Cowboy Marlin and I think at one time I tried it that gun and something didnt go right. Need to try some again. I do have a bunch of the shorter brass which has worked well. I used some 4198 in the past and have used it in a 444. But one day I had brain failure and sold the 444. Shouuld have kept it. When I get to load some of those 200 grainers I will make a report.
As to the longer brass in the 38-55 the only thing I've done so far is confirm that it fits the chamber of my gun as it should. I would suggest checking the fit in any individual gun before trying to load though. Got some shooting to do the next couple days and some work around the house and grandkids I seldom get to see coming Saturday but hope to start load development in the next few days somehow.
- Frontiersman
- Cowhand
- Posts: 117
- Joined: Thu Apr 28, 2016 9:20 pm

Re: Side Gate 38-55 Groove Diameter?
I believe they used it during WWII when they attacked German manufacturing plants. Didn't think they had .38-55s though. Must have been some cowboys in that war too.