Many new owners of
Mosin-Nagant rifles and carbines have encountered
what is commonly referred to as “sticky bolt syndrome”,
where the bolt tends to be difficult to open after
firing. This most often happens with the use of
lacquered steel cased ammunition but can also happen
with cases made from other materials.
headspace is correct (A “sticky bolt” on a rifle
that has been cleaned, has no burrs but hasn’t been head
spaced is an indication of overpressure. Don’t fire this
rifle again until it has been checked by a competent
gunsmith), there two probable reasons for this:
1) Cosmoline and old crud left in the chamber
2) A burr in the chamber
Lacquered steel cases (such as 60s Czech silver tip
ammo) are particularly problematic when there is
leftover cosmoline in the chamber. What happens is that
when fired, the lacquer and the cosmoline heat up & flow
together, forming a rough glue that makes it difficult
to open the bolt. The biggest problem with cosmoline in
the chamber is that it’s not usually easily detected.
When dry cosmoline forms a shellac-like coating on the
metal that can be difficult to detect.
Luckily both of these problems are easily fixed. We’ll
start off with the most common which is crud in the
The fix for this is simple. Here I have outlined the “at
home” method, with a note about the range method
Tools & equipment needed:
- End section of a cleaning rod
- 410 or 20 gauge brass brush
- (2) .410 or 20 gauge cotton swab
- Solvent: Hoppes No.9, Sweets, Ed’s Red, Acetone,
any good solvent that will eat away the cosmoline
- A drill
1) Remove the bolt from your rifle.
2) Attach the brush to the end of the cleaning
3) Chuck the cleaning rod into the drill.
4) Dip the brush into the solvent.
*WARNING* Do NOT let the brush come into
contact with the rifling. We just want to clean the
chamber, not wear down the barrel. While it may not do
much damage if the brush touches, why do any damage at
5) Put the cleaning rod through the receiver so
that the brush is inside the chamber but not touching
6) Using low to medium speed run the brush
clockwise around the chamber for 10 to 20 seconds.
7) Remove the drill, rod & brush from the rifle.
8) Using a lint free rag and your finger remove
as much cosmoline as you can.
9) Replace the brass brush on the cleaning rod
with the cotton swab.
10) Dip the cotton swab in the solvent, and
repeat steps 5-8.
11) At this point most of the cosmoline should be
gone. Replace the solvent & cosmoline soaked swab with a
12) Run the dry swab the same as above, but for
only 5 seconds.
This may not remove all the cosmoline in one go, but the
bolt should be easier to open afterwards. If the bolt is
easier to open but still “sticky”, simply repeat the
procedure until all the cosmoline is gone.
The preferred (and most fun!) method of cleaning
is the same as above, but it takes place at the range.
Hot cosmoline flows & is much easier to remove than when
The steps for range cleaning are:
1) Fire 5 shots or so until the chamber is good
and hot then open the bolt. The bolt will likely be
quite difficult to open by this time, a rubber mallet
can come in handy for this purpose.
2) Use your finger to run a lint-free rag dipped
in solvent around in the chamber, removing as much
cosmoline as you can.
3) Use the dry end of the rag to remove the
leftover solvent and some additional cosmoline.
4) Repeat steps 1-3 until the bolt is easy to
5) Done! Now, wasn’t that a fun way to clean?
If the bolt still has the same difficulty opening as it
did before cleaning the chamber may be an indication
that there’s a burr in the chamber. Again, this is
assuming that headspace has been checked and is correct.
If there are scratches on your casings this is a sure
sign of burrs.
Fixing burrs is also very easy:
Tools and Equipment needed:
1) Find the burr. This is easily done by running
your finger around the chamber.
2) Using the curved file, lightly file away the
burr until you can’t tell the difference between where
it was and the rest of the chamber by feel.
While a Dremel tool could be used for deburring, I
strongly recommend that it not be used. It’s far too
easy to grind off too much metal using a power tool. As
with everything else, it’s much easier to take away
material than it is to add it back on. Some patience and
a steady hand will get those burrs out
Clean and deburr your chamber and keep those bullets